I’ve never had to Add cups-pdf, it has always been installed when I install cups, from the Distro Repository. For me it has shown up in every application the offers printing.
Firefox, LibreOffice, kate, claws-mail, Kdevelop among others.
I’ve never seen that method for installing cups-pdf.
In fact cups-pdf is in the Manajaro Repos, and can be installed from pamac via GUI or CLI.