What to ask a Wireless Carrier for

Hello. I have an Airstream trailer that has the Airstream Connected system installed in it for mobile internet. This system includes the Pepwave MAX-BR1-MINI-LTE-US-T router. Currently, the system has an AT&T SIM in it, but the plan runs out next June. AT&T has dropped their unlimited data plan for this system so I’ll be shopping for a new plan.

My question is, when I talk to a wireless carrier, what am I asking for? I assume I want a data only plan. Is there specific terminology to use to get what I need?