SkyPrep integrates with Twilio for SMS-based notifications, although you will need an active Twilio account and number.
To set up the integration, click on the Settings button followed by Integrations.
Click Add to SkyPrep in the Twilio panel.
Enable the integration and enter the account credentials and number.
The information can be found in your Twilio dashboard.
After linking your account, test the integration with the Send Test Message button and turn on the notifications that you want sent via SMS.
In order for notifications to be sent to a user, they will need to have a phone number entered in their Cell field, as well as the Enable SMS Notifications setting turned on.
If you receive Error 21608 stating This number can send messages only to verified numbers, you can view the Twilio help article.