All SMS projects require an SMS connection to send and receive messages from users. Dimagi provides a number of shared connections for use in projects. Details on Dimagi's connections are available on these pages:
This tutorial will use one of Dimagi's international SMS connections, Twilio. This connection supports sending messages to many countries, but at a higher cost. If there is a specific connection that makes more sense in your country, feel free to use that instead.
Choose Twilio Connection
Go the Messaging tab and choose the SMS Connectivity page.
From the list of gateways, find MOBILE_BACKEND_TWILIO and click on the Set as Default button. This will setup the project to use Twilio to send messages by default.