Great!

In that case nostr:nprofile1qqsr3gwdr05shx5f35jpthqsrhcgwrc4kuh2y0xmpt0647kgp5p06zgp64szl, you should be able to find a couple Blossom servers here that would be happy to let you upload the PDF of your book:

https://blossomservers.com/

If you're up to the task,you can also run your own Blossom server. I am partial to the one built into Haven Relay. You can find the GitHub with installation instructions here:

https://github.com/bitvora/haven