Send SMS after registration
When somebody registers on your website, you can show this person a form asking for their telephone number to send them a welcome SMS.
Let's start from Trigger: Event Trigger (event means when somebody submits your registration form). Then, connect it with Action: Show a form with a request to provide his/her telephone number. Apply Delay to check if the person has submitted the form after 60 sec. If yes, then Action: Send SMS.