Photo book

Hello Beachmimi1,

Thank you for using Apple Support Communities! I understand that you are unable to purchase a book made in the Photos app on your Mac. Built-in print products services have been discontinued as of September 30, 2018.

You can now use Project Extensions to create and order print products using a third-party:

Create and order print products in Photos with Project Extensions - Apple Support

Take care!

Are you able to create a PDF file for that book?  If so there's a 3rd party book provider which used to do the printing for Apple, Mimeo, that will take PDF files created by iPhoto and Photos and print and bind books and calendars. 

Also you can upload the PDF file to PrestoPhotos which can print and bind books and calendars from iPhoto or Photos pdf files.  They've been doing it for some time now.  

Use the PrestoPhotos or Mimeo links above for direct access to the PDF file uploading and book/calendar ordering page for each site.