Cannot connect to AT&T

I have an active AT&T sim card i am trying to use with the NOVA and a Raspberry Pi. When I run AT+COPS=? i get the response:
+cops: (3, “AT&T”, “AT&T”, “AT&T”…

but when i do AT+CGDCONT=1, “IP”, “AT&T” i get the response:
+CME ERROR: operation not supported.

CGDCONT is for setting the APN which may not be what you want to do there. If it’s an AT&T SIM, you probably want to leave the APN blank