Apple Books is a great way to listen Audible audiobooks offline on macos devices. It is quite handy to have everything in one place. But looks like integration between these two are not perfect. When you try to follow official instructions there is a chance that after you get your signed link for Apple Books it’s not gonna be accepted by the app.

So here is the workaround:

  1. Open audiobook file
  2. Apple Books: Authorize This Computer
  3. Apple Books: QUIT FROM THE APP!
  4. Audible: Activate in (iTunes) Apple Books
  5. Open signed link specifically in the Apple Books app (Not Music)