I published with iBook Author which is now Apple Books, but it doesn't know it's my book so I can't login to manage it

I've tried unsuccessfully for 2 years to login to manage my published ebook now on Apple Books. About 10 years ago when I published on iBook Author all was well. I think I created a unique Apple ID for my identity as the book author. But when iBook Author became iTunes books and now Apple Books, Apple keeps transferring my book to their current site and yes it's still there, but the site doesn't know it's MY book. The many tickets I've opened have gone nowhere, and legal got involved once and said they can't prove it's my book (I can prove it; I have the original content published to their site). My latest Apple support ticket was from a week ago where the support person said she was going to send a simple article on how to reset my Apple ID password (saying that would resolve the issue?) but when I clicked the follow-up email "with 4 articles" there was nothing there and the ticket had nothing to do with this issue. Apple doesn't have a clue and won't help me. Does anyone have any ideas how to help so I can affiliate my book with me and login and manage my book?