Tomcat why do you want sms? 😃 jihad style...
Look, im sure you can have mobile data (internet), maybe you already have. So why dont you do wake-on-lan? This can be done only on lan, meaning the machine that sends this command needs to be on lan network with other devices.
So, all you need to do is create VPN to your home network, using wireguard. put wireguard app on your phone, flick a switch and youre connected to your lan from any network. 🙂..
I have a setup like this. Some routers have built in software -wakeonlan so that you only need to conenct to your router which is already facing the public network..
I dont know how to do it by sms but im sure there are ways, but sms could be blocked with them drone blockers that they use these days.. whole region could be under interference.. so im not sure that its reliable.. optical network which most of modern networks are made of are more reliable.. but not certain..
I dont get it why dont you use wireguard? it is self hostable application that inly needs one port to be open, and you can conenct to your network from outside networks... it has client apps for phones, windows, linux, mac..
Right now im playing with home assistant, where you can control your home from the webui. In there you can add integration/addon - wakeonlan, and then create button in the webui to trigger that. Its more handy than trying to ssh into the server and type out the mac address in the terminal on the phone D: