How to create a form with user SMS notification per submission?

I’m creating a simple registration (without password, without creating account) form that targetting elderies who mostly didn’t have email address or didn’t know how to use email properly.

I wish to send SMS notification as per each submission to notify their registration is successful.

Anyone can share which combination of plugin can be done, particularly using Twilio (or any other SMS gateway is fine, as long as supporting South East Asia countries like Singapore, Malaysia, Indonesia, etc).

Greatly appreciated for any advice / recommendation 🙏