ONLY new user pop up

How do you set it to only pop up when it’s a new user, i.e. visiting for the first time, so you can build a list? I want to ensure the users are not seeing it after they sign up. If they get the pop up but don’t sign up, will it pop up the next time they visit? Thanks!

https://www.ads-software.com/plugins/mailchimp-forms-by-mailmunch/