Where do I find the APN for an XBee 3 cellular modem with AT&T SIM?

The documentation suggests knowing the APN to do some of the examples, but nowhere can I find the APN. Am I supposed to just use common AT&T APNs?

If they are from Digi, the APN will be most likely 10569.mcs

The APN for your SIM would have to come from the provider. For example, if you have a SIM ordered from online AT&T IoT Marketplace, the APN will be m2m.com.attz for LTE-M and m2mnb16.com.attz for NB-IoT.

If you really don’t know the APN, you can try using the “-”, which may or may not work.

We bought these, https://www.digikey.com/en/products/detail/digi/XK3-C-A2-T-UB/12750013.

They simply came with the AT&T SIM in them.

When using XCTU, it shows “-”, but I assumed it was a place holder, didn’t realize it may be valid.