I have been using my ESP8266 module with my Arduino on my university's Wi-Fi network, which only requires a password to log on to.
The university will soon terminate that Wi-Fi network and replace it with one that requires a username and password to log on.
What would that AT command be to connect to such a network?
Edit: I have since found out that the university has changed the network so that a user can "connect" to the network and then enter their university id/password in a captive portal to gain internet access (and perhaps other features of the network). Also, I have since learned how to overwrite the firmware on my esp-01 so that I no longer need to use the AT commands -- in fact, I can program it in the Arduino IDE just as I would with another esp8266-based device, such as the NodeMCU.