[ramy_d]

what's the alternative for something straightforward like that?

[RobotToaster]

A raspberry pi with a 4g hat?

Overkill I suppose, in the past for similar stuff I've used a microcontroller with a GPRS modem, but since the 2g switch off I'm not sure it can be done that simply.

[sparrish]

4g hats don't even work with many providers anymore since many US carriers are whitelisting only their allowed devices to send SMS on their networks.

[paulddraper]

There isn't one. This headache is legal, not Twilio

[netr0ute]

There is, it's called a USB 4G modem that plugs straight into whatever server you want.