I’m picking an older LTE only chip that I’m familiar with and a compatible enclosure. There might be cheaper.
It’s far from plug and play as you’ll either need to come up to speed with AT command or research if some libraries interact it. Edit: I’d look at what OpenWRT is using - I’ve plugged these into those and had a relatively plug and play experience.
Entirely possible this isn’t what you’re looking for - what’s a link to one of these dongles on Amazon?