How do I fix Audible audio files not playing on my M2 Mac mini?

Using a M2 Mac mini running the latest OS. Audible audio files were playing fine out of Apple Books a month or so ago. Now, not one plays. Keeps asking for authorisation. Followed the on-screen instructions, but keep being directed back to my Mac after going through various hoops. Audible support has ran out of ideas. Hence the community. Look forward to hearing any suggestions.

[Re-Titled by Moderator]