Restrict access to explicit books and audiobooks in Books on Mac
You can prevent people who use your Mac from accessing the Book Store or Audiobook Store and from getting books with explicit content. If you set up Family Sharing, you can turn on Ask to Buy so that you’re asked to approve purchases for certain family members.
Control access to the Book Store and Audiobook Store and explicit content
On your Mac, choose Apple menu > System Settings, then click Screen Time in the sidebar. (You may need to scroll down.)
Click Content & Privacy on the right, then turn on “Restrict explicit content, purchases, downloads and privacy settings”.
Do any of the following:
Disable the Book Store and Audiobook Store: Click App Restrictions, then turn off Allow Book Store.
Restrict books with explicit content: Click Store Restrictions, then turn off Allow Explicit Books.
Turn on Ask to Buy
Ask to Buy is on by default for children under 13, and can be turned on for family members under 18. (specific age limits might vary in different countries or regions). See Set up Family Sharing.
On your Mac, choose Apple menu > System Settings, then click Family.
Click a family member, click Ask To Buy in the sidebar, then turn on Require Purchase Approval.