Question for any US-based PinePhone aficionados: what carrier are you using (where/how did you get a SIM card)?

I recently got an ATT pre-paid SIM (that I was planning on putting in an Android phone eventually). I thought I would give it a try in the PinePhone just to see what happens and found that it would not activate... (Note that this was just a normal pre-paid SIM direct from ATT and not from some 3rd-party MNVO that might require an app to activate. When I eventually installed the SIM in the Android phone it was able to activate as expected without installing any apps).