Simply include each item you want to use and already have (e.g. phone number, email, etc.) as a Custom Variable or as a custom data field. Regardless of which you use, you should still ask the respondent a yes or no question at the end of the survey to see if you can follow up with them.
4 Ways to Send an Anonymous Text - wikiHow Mar 01, 2020 How to Send Emails Anonymously - AllTopStartups Feb 19, 2019
Mar 31, 2020
Jan 13, 2017 How To Send a Truly Anonymous Email - Tech Junkie
How To Send an Anonymous Text - Tech Junkie
How to Get a Free Email Account for Email Anonymity Nov 11, 2019 How To Create An Anonymous Email (Full Guide With May 22, 2018 How to Create an Anonymous Email to Protect Your Identity Feb 10, 2020 How Do I Send an Email that Can't Be Traced Back to Me