Where is "authorizations" in "books"?

The instructions on this page...

Authorize your Mac to get purchases from the Book Store, Audiobook Store, or Audible website - Apple Support

...say "In the menu bar, choose Account > Authorizations > Authorize This Computer." But "Authorizations" doesn't appear anywhere in my "Account" menu. Did it get moved somewhere else? Or is there another way to authorize?

I'm logged in to the same account I used to purchase the books, and the books I purchased are listed in the "Books" app. But when I click on a book it says "Your computer is not authorized. You must authorize this computer from the Account menu before you can download previous purchases."

I've got the latest MacOS Sequoia 15.0.1, Books version 7.0.

Any suggestions appreciated! Thanks.