Here: ^HCSQ:"LTE",77,67,121,20
I also found out that if I create the network profile directly in Luci, it's much easier and faster to re-establish the modem connection in GL-iNet UI:
Another benefit of setting this up in Luci is that the E3372 connects to the Internet automatically when I plug it to the MT3000 (without going to the UI and click Auto Setup).
For auto re-connection, I use this script: openvpnForNordvpn/etc/init.d at master · oilervoss/openvpnForNordvpn · GitHub