If you’re not working with quectel or modemmanager the command is somewhat different. Basic knowledge of AT is required. Some people use socat or minicom although modemmanager is a lot easier and in many cases already handling the network interface.
All I can say is that the netgear hotspot that AT&T sells goes pretty cheap used/unlocked on Amazon and you can do “things” to it with free tools online.
Yeah I called twice, second time got transfered from CS to actual tech to explain it all. Esim and VPN never came up, they were baffled, promised to follow up, and now a month later I get the texts again so clearly nothing changed.
And the CS rep was mad because I wasn’t being charged for maxing my hotspot so what problem could I possibly have lol. I couldn’t get them to understand that if one thing was being incorrectly tracked then I had no reason to trust they were tracking other things correctly.