Gravity Forms Twilio Add-On: I want to be able to send SMS to people's phone number that they inserted into the form

Hello, I'm having trouble with the Gravity Forms Twilio Add-On. I want to be able to send messages to people's phone numbers that were inserted into the form. For example "User A", "User B" and "User C" enter their phone numbers in the form. Now I want to be able to send them a SMS by using the Phone Number Merge Tag in the "To Number" field.