How can I design a cover page of a book in Adobe Frame Maker?

I have a free template which comes with a working sample as well. You can download it for free here:

https://framemaker.dk/en/shop/product/44-quiote-us-letter-template-for-technical-documentation

It is quite extensive, really, with options for export to HTML5 and other nice stuff.

And, as asked on your prior cover thread:

How published?

Print publication usually requires an oversized page that includes front-spine-rear cover content.

For PDF/eBook, I add a .fm file for the front cover, and another for the back. It's no different than any other book content in that regard. What goes to the print shop, on the other hand, is a PDF with just the inside pages, and a separate PDF with the oversize wrap-around cover.

Hi Amit:

There are two examples of cover pages in Standard Templates: one for the User Guide and one for the Parts Catalog. You might want to open both of them and take a look to see how they're set up, and potentially replace their information with yours. Once they're done, you can just add them to the top of your list in your book window.

~Barb