When I open ADE through itunes to transfer my downloaded book from my Mac to my iPad I cannot see the book in the library. How can I transfer the book to ipad.

I‌ downloaded a book to Apple computer . the publishher required that i have ADE and Bluefire reader which I have. I cdownloaded the book and can open it. However when I use iTunes to transfer the book to my ipad and select ADE as the app where I have the downloaded book, I cannot see the book in the library. As a result I cannot transfer the book to my iPad.