Make sure that you have the SMS feature enabled, and enough credit to use.
in the form (once you've filled out the fields that you would like to be done) you can select Convert to Webform under the Title, and Save. Then you will have more options appear.
Select Copy Link, and then select the Quick Send button in the top menu > select Message. You can then select the Contact you're sending to, and paste the webform link in the SMS body, along with a message for the client, and send. The client will receive the link to the webform which they can then complete.
