Apple Books to iPod classic

I presume you tried the obvious?

If that doesn't work, I think you may find you need to use a device where you can sign into your Apple-ID in order to read or listen to any Apple Books products. This is because of DRM and the fact you don't actually legally own the books.

iPod classic does not fit into that category unfortunately.

Hey there Toxicbob,

Thanks for reaching out to Apple Support Communities. I understand you want to know how to sync your audiobooks to an iPod classic or non-Apple MP3 player. I’ll be happy to help.

You’ll want to use Finder to sync your audiobooks and other content to your iPod. Take a look at this article for more info:

Use the Finder to sync your iPhone, iPad, or iPod with your computer

With a 3rd-party MP3 player, you’ll want to refer to the manual of the device to verify how to sync your media over. Some have their own apps that you use and others may work like a file system. 

Regards.