Display Condition: Show for X visitors

If you want to promote something to only people who are logged in to your website (or only to those not logged in) then this is the option you want.

When editing your popup, click on Display Conditions.

Inside of Edit Display Conditions, you will look for and turn on Show for X visitors, and in the dropdown that appears you can select one of the options.

When you are happy with it, you can close it (using the x at the top-right corner), then save / publish your popup.