Firefox doesn't want others PDF Printers than the commercial "Full Web Page Screenshots" (ask u why?!!)!! "Print pages to Pdf" is the best but has been killed by Firefox. Let's retrieve it on fab' Pale Moon!!
When I uniinstalled this application it left something inside my browser that causes a message "Thanks for using Web to PDF" every time the browser is activated. It does work but don't expect to uninstall it unless you want to remove and re-install your browser(s) in order to get rid of the nag message.
Does not work, but pushes the need to buy the Pro version instead. There are many similar dishonest plugins pretending to offer the same service. PDF Mage has a high review score, so I will try that one. This one will be removed.