To set your paywall live, click the Publish button in the top-right side of the editor:

Setting your paywall live doesn’t necessarily mean that users will see it. You’ll first need to associate a paywall with a campaign. From there, either a user is matched to an audience filter or a placement is evaluated which results in a paywall being presented.

Changes you make are saved locally, even if you haven’t published the paywall. Refreshing won’t erase progress if you close the tab and come back later, unless you sign out.