Download PDF to Apple Books no longer possible?

According to the Apple instructions issued only in January this year I can open a PDF in Safari, click on the share/download icon and then tapping Copy to Books in the drop down

This is a big fat lie, that option does not exist

I can choose Download to Files but this does not for some reason give me the option of downloading to Books any longer

If i click Save it seems to download, not sure where it goes, there is then a little download button Safari which seems to open the downloaded file, but it is not accessible through the Books app, which I'd prefer, and which used to be the easy default does