The fastest way to preview a screener is to use the quick dropdown at the top of the page when logged in to Ethnio:
That opens a new tab where you can look at your screener as a link or web intercept, and there's a toggle you can use to turn on asterisks that show any logic in your questions, such as qualifying questions, filters for 3rd Party URL, or drill down questions:
Keep in mind if you see any asterisks, that is only in preview mode and your respondents will never see those. This is designed to show you which responses will yield a "congrats" page. Lots more info about how logic works here.