GL X3000 Difficulty connecting on AT&T Network

Received my router today. Cannot get it to connect with a cellular connection to AT&T. was getting a sim not but now ive progressed to a Some SIM Cards have special use restrictions such as the need to use a specific APN.

Anyone use AT&T successfully? any insight as to what settings to use?

YES, some specific APNs are required.

You can check which APN you are using on your phone.