i was programming my node mcu i modified the code and got a complination error but when i compiled the original code i got no error
modified code


    #include "arduino_secrets.h"
    #include "thingProperties.h"
    
    // define the GPIO connected with Relays and switches
    #define RelayPin1 5  //D1
    #define RelayPin2 4  //D2
    #define RelayPin3 14 //D5
    #define RelayPin4 12 //D6
    
    #define RelayPin5 2  //d4
    #define RelayPin6 0   //D3 
    #define RelayPin7 13  //D7
    #define RelayPin8 15   //d8
    
    #define wifiLed   16   //D0
    
    int toggleState_1 = 0; //Define integer to remember the toggle state for relay 1
    int toggleState_2 = 0; //Define integer to remember the toggle state for relay 2
    int toggleState_3 = 0; //Define integer to remember the toggle state for relay 3
    int toggleState_4 = 0; //Define integer to remember the toggle state for relay 4
    int toggleState_5 = 0; //Define integer to remember the toggle state for relay 5
    int toggleState_6 = 0; //Define integer to remember the toggle state for relay 6
    int toggleState_7 = 0; //Define integer to remember the toggle state for relay 7
    int toggleState_8 = 0; //Define integer to remember the toggle state for relay 8
    
    void relayOnOff(int relay) {
    
      switch (relay) {
        case 1:
          if (toggleState_1 == 0) {
            digitalWrite(RelayPin1, HIGH); // turn on relay 1
            toggleState_1 = 1;
            Serial.println("Device1 ON");
          }
          else {
            digitalWrite(RelayPin1, LOW); // turn off relay 1
            toggleState_1 = 0;
            Serial.println("Device1 OFF");
          }
          delay(100);
          break;
        case 2:
          if (toggleState_2 == 0) {
            digitalWrite(RelayPin2, HIGH); // turn on relay 2
            toggleState_2 = 1;
            Serial.println("Device2 ON");
          }
          else {
            digitalWrite(RelayPin2, LOW); // turn off relay 2
            toggleState_2 = 0;
            Serial.println("Device2 OFF");
          }
          delay(100);
          break;
        case 3:
          if (toggleState_3 == 0) {
            digitalWrite(RelayPin3, HIGH); // turn on relay 3
            toggleState_3 = 1;
            Serial.println("Device3 ON");
          } else {
            digitalWrite(RelayPin3, LOW); // turn off relay 3
            toggleState_3 = 0;
            Serial.println("Device3 OFF");
          }
          delay(100);
          break;
         case 4:
          if (toggleState_4 == 0) {
            digitalWrite(RelayPin4, HIGH); // turn on relay 3
            toggleState_4 = 1;
            Serial.println("Device4 ON");
          } else {
            digitalWrite(RelayPin4, LOW); // turn off relay 3
            toggleState_4 = 0;
            Serial.println("Device4 OFF");
          }
          delay(100);
          break;
         case 5:
          if (toggleState_5 == 0) {
            digitalWrite(RelayPin5, HIGH); // turn on relay 3
            toggleState_5 = 1;
            Serial.println("Device5 ON");
          } else {
            digitalWrite(RelayPin5, LOW); // turn off relay 3
            toggleState_5 = 0;
            Serial.println("Device5 OFF");
          }
          delay(100);
          break;
         case 6:
          if (toggleState_6 == 0) {
            digitalWrite(RelayPin6, HIGH); // turn on relay 3
            toggleState_6 = 1;
            Serial.println("Device6 ON");
          } else {
            digitalWrite(RelayPin6, LOW); // turn off relay 3
            toggleState_6 = 0;
            Serial.println("Device6 OFF");
          }
          delay(100);
          break;
         case 7:
          if (toggleState_7 == 0) {
            digitalWrite(RelayPin7, HIGH); // turn on relay 3
            toggleState_7 = 1;
            Serial.println("Device7 ON");
          } else {
            digitalWrite(RelayPin7, LOW); // turn off relay 3
            toggleState_7 = 0;
            Serial.println("Device7 OFF");
          }
          delay(100);
          break;
        case 8:
          if (toggleState_8 == 0) {
            digitalWrite(RelayPin8, HIGH); // turn on relay 4
            toggleState_8 = 1;
            Serial.println("Device8 ON");
          }
          else {
            digitalWrite(RelayPin8, LOW); // turn off relay 4
            toggleState_8 = 0;
            Serial.println("Device8 OFF");
          }
          delay(100);
          break;
        default : break;
      }
    }
    
    void setup() {
      // Initialize serial and wait for port to open:
      Serial.begin(9600);
      // This delay gives the chance to wait for a Serial Monitor without blocking if none is found
      delay(1500);
    
      // Defined in thingProperties.h
      initProperties();
    
      // Connect to Arduino IoT Cloud
      ArduinoCloud.begin(ArduinoIoTPreferredConnection);
    
      setDebugMessageLevel(2);
      ArduinoCloud.printDebugInfo();
    
      pinMode(RelayPin1, OUTPUT);
      pinMode(RelayPin2, OUTPUT);
      pinMode(RelayPin3, OUTPUT);
      pinMode(RelayPin4, OUTPUT);
      pinMode(RelayPin5, OUTPUT);
      pinMode(RelayPin6, OUTPUT);
      pinMode(RelayPin7, OUTPUT);
      pinMode(RelayPin8, OUTPUT);
    
      pinMode(wifiLed, OUTPUT);
    
      digitalWrite(RelayPin1, LOW);
      digitalWrite(RelayPin2, LOW);
      digitalWrite(RelayPin3, LOW);
      digitalWrite(RelayPin4, LOW);
      digitalWrite(RelayPin5, LOW);
      digitalWrite(RelayPin6, LOW);
      digitalWrite(RelayPin7, LOW);
      digitalWrite(RelayPin8, LOW);
    
      digitalWrite(wifiLed, HIGH);  //Turn ON WiFi LED
    }
    
    void loop() {
      ArduinoCloud.update();
      
    
      if (WiFi.status() != WL_CONNECTED)
      {
        digitalWrite(wifiLed, HIGH); //Turn ON WiFi LED
      }
      else{
        digitalWrite(wifiLed, LOW); //Turn OFF WiFi LED
      }
    }

the original code 


    #include "arduino_secrets.h"
    #include "thingProperties.h"
    
    // define the GPIO connected with Relays and switches
    #define RelayPin1 5  //D1
    #define RelayPin2 4  //D2
    #define RelayPin3 14 //D5
    #define RelayPin4 12 //D6
    
    #define SwitchPin1 10  //SD3
    #define SwitchPin2 0   //D3 
    #define SwitchPin3 13  //D7
    #define SwitchPin4 3   //RX
    
    #define wifiLed   16   //D0
    
    int toggleState_1 = 0; //Define integer to remember the toggle state for relay 1
    int toggleState_2 = 0; //Define integer to remember the toggle state for relay 2
    int toggleState_3 = 0; //Define integer to remember the toggle state for relay 3
    int toggleState_4 = 0; //Define integer to remember the toggle state for relay 4
    
    void relayOnOff(int relay) {
    
      switch (relay) {
        case 1:
          if (toggleState_1 == 0) {
            digitalWrite(RelayPin1, HIGH); // turn on relay 1
            toggleState_1 = 1;
            Serial.println("Device1 ON");
          }
          else {
            digitalWrite(RelayPin1, LOW); // turn off relay 1
            toggleState_1 = 0;
            Serial.println("Device1 OFF");
          }
          delay(100);
          break;
        case 2:
          if (toggleState_2 == 0) {
            digitalWrite(RelayPin2, HIGH); // turn on relay 2
            toggleState_2 = 1;
            Serial.println("Device2 ON");
          }
          else {
            digitalWrite(RelayPin2, LOW); // turn off relay 2
            toggleState_2 = 0;
            Serial.println("Device2 OFF");
          }
          delay(100);
          break;
        case 3:
          if (toggleState_3 == 0) {
            digitalWrite(RelayPin3, HIGH); // turn on relay 3
            toggleState_3 = 1;
            Serial.println("Device3 ON");
          } else {
            digitalWrite(RelayPin3, LOW); // turn off relay 3
            toggleState_3 = 0;
            Serial.println("Device3 OFF");
          }
          delay(100);
          break;
        case 4:
          if (toggleState_4 == 0) {
            digitalWrite(RelayPin4, HIGH); // turn on relay 4
            toggleState_4 = 1;
            Serial.println("Device4 ON");
          }
          else {
            digitalWrite(RelayPin4, LOW); // turn off relay 4
            toggleState_4 = 0;
            Serial.println("Device4 OFF");
          }
          delay(100);
          break;
        default : break;
      }
    }
    
    void manual_control() {
      //Manual Switch Control
      if (digitalRead(SwitchPin1) == LOW) {
        delay(200);
        relayOnOff(1);
      }
      else if (digitalRead(SwitchPin2) == LOW) {
        delay(200);
        relayOnOff(2);
      }
      else if (digitalRead(SwitchPin3) == LOW) {
        delay(200);
        relayOnOff(3);
      }
      else if (digitalRead(SwitchPin4) == LOW) {
        delay(200);
        relayOnOff(4);
      }
    }
    
    void setup() {
      // Initialize serial and wait for port to open:
      Serial.begin(9600);
      // This delay gives the chance to wait for a Serial Monitor without blocking if none is found
      delay(1500);
    
      // Defined in thingProperties.h
      initProperties();
    
      // Connect to Arduino IoT Cloud
      ArduinoCloud.begin(ArduinoIoTPreferredConnection);
    
      setDebugMessageLevel(2);
      ArduinoCloud.printDebugInfo();
    
      pinMode(RelayPin1, OUTPUT);
      pinMode(RelayPin2, OUTPUT);
      pinMode(RelayPin3, OUTPUT);
      pinMode(RelayPin4, OUTPUT);
    
      pinMode(wifiLed, OUTPUT);
    
      pinMode(SwitchPin1, INPUT_PULLUP);
      pinMode(SwitchPin2, INPUT_PULLUP);
      pinMode(SwitchPin3, INPUT_PULLUP);
      pinMode(SwitchPin4, INPUT_PULLUP);
    
      //During Starting all Relays should TURN OFF
      digitalWrite(RelayPin1, HIGH);
      digitalWrite(RelayPin2, HIGH);
      digitalWrite(RelayPin3, HIGH);
      digitalWrite(RelayPin4, HIGH);
    
      digitalWrite(wifiLed, HIGH);  //Turn OFF WiFi LED
    }
    
    void loop() {
      ArduinoCloud.update();
      
      manual_control(); //Control relays manually
    
      if (WiFi.status() != WL_CONNECTED)
      {
        digitalWrite(wifiLed, HIGH); //Turn OFF WiFi LED
      }
      else{
        digitalWrite(wifiLed, LOW); //Turn ON WiFi LED
      }
    }
    
    void onSwitch1Change() {
      if (switch1 == 1)
      {
        digitalWrite(RelayPin1, HIGH);
        Serial.println("Device1 ON");
        toggleState_1 = 1;
      }
      else
      {
        digitalWrite(RelayPin1, LOW);
        Serial.println("Device1 OFF");
        toggleState_1 = 0;
      }
    }
    
    void onSwitch2Change() {
      if (switch2 == 1)
      {
        digitalWrite(RelayPin2, HIGH);
        Serial.println("Device2 ON");
        toggleState_2 = 1;
      }
      else
      {
        digitalWrite(RelayPin2, LOW);
        Serial.println("Device2 OFF");
        toggleState_2 = 0;
      }
    }
    
    void onSwitch3Change() {
      if (switch3 == 1)
      {
        digitalWrite(RelayPin3, HIGH);
        Serial.println("Device2 ON");
        toggleState_3 = 1;
      }
      else
      {
        digitalWrite(RelayPin3, LOW);
        Serial.println("Device3 OFF");
        toggleState_3 = 0;
      }
    }
    
    void onSwitch4Change() {
      if (switch4 == 1)
      {
        digitalWrite(RelayPin4, HIGH);
        Serial.println("Device4 ON");
        toggleState_4 = 1;
      }
      else
      {
        digitalWrite(RelayPin4, LOW);
        Serial.println("Device4 OFF");
        toggleState_4 = 0;
      }
    }

i have included the arduino_secrets and thingproperties in my both pieces of code the difference is that i wanted 8 relay pins to be configured instead of 4 pins 
please ask if any thing is needed from me


this was the exact error 

    C:\Users\akki kisu\Documents\Arduino\libraries\ArduinoIoTCloud\src\property\Property.cpp:25:19: note: '#pragma message: No RTC available on this architecture - ArduinoIoTCloud will not keep track of local change timestamps .'
       25 |   #pragma message "No RTC available on this architecture - ArduinoIoTCloud will not keep track of local change timestamps ."
          |                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    c:/users/akki kisu/appdata/local/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/3.0.4-gcc10.3-1757bed/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld.exe: sketch\Code_NodeMCU_Alexa_ArduinoIotCloud_4Relays.ino.cpp.o:(.text._Z14initPropertiesv+0x1c): undefined reference to `_Z15onSwitch1Changev'
    c:/users/akki kisu/appdata/local/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/3.0.4-gcc10.3-1757bed/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld.exe: sketch\Code_NodeMCU_Alexa_ArduinoIotCloud_4Relays.ino.cpp.o:(.text._Z14initPropertiesv+0x34): undefined reference to `_Z15onSwitch2Changev'
    c:/users/akki kisu/appdata/local/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/3.0.4-gcc10.3-1757bed/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld.exe: sketch\Code_NodeMCU_Alexa_ArduinoIotCloud_4Relays.ino.cpp.o:(.text._Z14initPropertiesv+0x40): undefined reference to `_Z15onSwitch3Changev'
    c:/users/akki kisu/appdata/local/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/3.0.4-gcc10.3-1757bed/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld.exe: sketch\Code_NodeMCU_Alexa_ArduinoIotCloud_4Relays.ino.cpp.o:(.text._Z14initPropertiesv+0x4c): undefined reference to `_Z15onSwitch4Changev'
    collect2.exe: error: ld returned 1 exit status
    exit status 1
    Error compiling for board NodeMCU 1.0 (ESP-12E Module).