Photo project

Apple got out of the business of printing books, calendars, cards, and such almost two years ago. It was widely discussed in the tech press at the time.

Since then, you have to use software provided by other print vendors to create these projects and send the projects to those vendors. Current versions of Photos provide the framework to support that third-party software.

If you have created print projects using older versions of Photos and are still running that older Photos, you may be able to create PDF preview copies of the projects and send the PDFs to a print vendor.

I said above, "Current versions of Photos provide the framework to support that third-party software." That framework does interface with the user in the way you describe, through the File > Create... menu inside Photos.

Here's an example in Photos 5.0 (macOS Catalina 10.15.6):

"Mimeo Photos" is a Photos Extension created by a third-party print vendor, which can be invoked as shown inside Photos to create (in this instance) a photo book. There are others; that just happens to be the only one installed on my example system capable of creating photo books.

The "App Store..." entry in the menu lets you download others, but you have to be at a system level and Photos version capable of supporting them. That's what the message about updating means.

Are you sure he ordered through Apple, rather than Mimeo or one of the other third parties? Some of them are the same companies that were doing the printing for Apple.

Did you ask him how he ordered?