Perhaps the question to ask the local company is if they provide an API service so that you can use Power Automate to send SMS messages through their gateway.
I've have used a local service similar to Twilio to send SMS messages. Although they don't have a Power Automate connector, they do provide an API which can be used to send messages:

Unfortunately, the HTTP action is a Premium connector and you may need to "upgrade" your power automate license to use it.
Ellis