Do you know, Google is gonna banned you after showing adsense ads into a pop-up or floating screen?
If yes, then why you searched for it! Many new bloggers want to earn more by showing adsense ads on a pop-up screen but after some time, they get banned. Before taking any step, you should view Google's Terms and Conditions which may helps you not to get banned by Adsense. Also see other tips for not getting banned by Google. Best step is Adding ads between your blog posts which can also let you earn more.
If you are still interested in showing ads in the pop-up or floating screen to maximize your earnings then, follow the below steps.
Go to Blogger Dashboard >> Layout.
In the sidebar or anywhere, click add a widget.
Add Below pop-up widget code there and save the Gadget.