In order to enable the print option on a flipbook, when editing your publication, go to the Customize tab and check the Enable PDF Print option.
After you do that, hit next and publish your flipbook. Checking this option will add a button in the top part of the screen when viewing a flipbook in full-screen mode.
When clicked, it will generate a PDF that you (and your readers) can print using own printers.
Important: this feature is available for all premium users, and it works for all flipbooks, including those which were created from scratch in our online editor.
If you want to know more details, please read this article.