Apple does no longer offer any print services. The last orders had to be placed by September 30.
Apple's statement about why this changed: Use Project Extensions to order print products in Photos after September 30, 2018 - Apple Support
To give users access to a broader variety of print services, macOS High Sierra introduced Photos Project Extensions which integrate directly with the Photos app. In macOS Mojave, Photos will transition entirely to Photos Project Extensions. Users will be able to print and update their existing projects using these new services, and will gain access to a broader variety of options.
You now have to use project extensions to create books in Photos. The project extensions allow you to order the books from third-party services. The Mimeo extension allows you to convert existing books, and you can edit them further in Mimeo.
For background reading on the new way books are handled by Photos:
See: Old Toad: Post 9/30/2018 Printing Options for Photos
and also: Use Project Extensions to order print products in Photos after September 30, 2018
Create and order print products in Photos with Project Extension
In Photos 4.0 on Mojave all tools to create native Apple print products (Cards, books, Calendars) have been completely removed. Install project extensions, for example Mimeo; the books you create with this extension offer similar layout to the Apple Books.
