(From public article)

Changing APN for T-Mobile and multi-carrier SIMs such as Twilio, Teal, Hologram, etc.

Note: Changing APN for AT&T and Verizon requires additional steps. See instructions at bottom of this page.

Step 1

• Connect gateway to ethernet.

• Locate the gateway’s IP address (you can use an IP scanner).

• Get gateway’s password, which is the serial number on the sticker on the bottom of the gateway.

• SSH into gateway using a command line interface program like Terminal on Mac or Command Prompt on PC:
  ssh root@192.168.2.xxx

• Password is the gateway serial number.

• Enter following commands to check the system version, current firmware, and current APN:

...

konaLTEmodem.py -c  'at+cgdcont=1,"IP","DESIRED APN HERE","0.0.0.0",0,0'

...

system_version
konaLTEmodem.py -c "'at!gobiimpref?"'
konaLTEmodem.py -c "AT+CGDCONT?"
/opt/chirpstack-gateway-bridge/chirpstack-gateway-bridge version
/opt/mydevices/dps-client -v
ifconfig eth0 | grep HWaddr

Output will look like this:

...

...