How to print a 5 x 7 folded greeting card in Photos?

Here is my newly created functional workaround:

1. Open another program (like Preview) and select print (but don't actually print!). Then under "Paper Size" go to "Manage Custom Sizes..." [this step is necessary because Apple Photos does not allow you to add a custom paper size).
2. Create a new custom paper size: 7 in x 10 in with non-printable area as user-defined: Top (3.85 in), Left/Right/Bottom (.2 in). Name it something like "5 x 7 photo greeting card"
3. Close without printing
4. Open Photos, select photo, and hit print.
5. Make sure that you select the newly created custom page size to print on.
6. Select "Custom" size and set photo size to 6.6 in by 4.57 in.
7. Print as usual.

The result is the whole photo prints on the bottom half of the page and then you can fold it in half to make your greeting card. I had to fiddle with the custom size and non-printable area settings (no idea why it doesn't actually correspond to the actual paper size), but these are the settings that are working for me. You may have to twiddle with them to get them to work for your printer.

Are you able to bring up the print command from the project menu? Any time I create a greeting card project (or I just tried it with a book), the print command is grayed out as shown in the original post. That's what disappeared for me in the last month or so, which I think coincides with Apple discontinuing the commercial print service for projects (I keep getting the attached window reminding me of this).

The PDF thought was a good one but doesn't look like it will work either because the orientation, size, and photo placement on the page aren't correct for a foldable card.

But step 1 in both of those tutorials is "bring up the Print window" which is grayed out now. Hence my question whether it is grayed out for you as well.