The SMS Notifications add-on uses Twilio‘s API to send SMS messages.
To start sending SMS notifications to your customers, you will first have to sign up for a Twilio account and add your API keys to the plugin.
Instructions on how to get the API keys and configure the add-on can be found in Settings → SMS.
After configuring the add-on, you will have to set up the notifications from Form → SMS Notifications.
We highly recommend enabling the Phone Number Stylised UI option in Settings → Form. This will provide a better user experience for your customers.