Hmm, I thought Mac users had that built in to the Print dialog somewhere. Not any more?

I don't have a Mac, but I found this article:

https://athelp.sfsu.edu/hc/en-us/articles/217975108-How-to-save-a-document-as-PDF-on-Mac-from-Firefox-

Does that work on yours?

Interesting that you know I posted this question from a Mac. Thank you, this seems to have resolved the problem. Thank you for always being this helpful.

Hope this will be added on Windows soon, too.

Thanks for the update.

Yes, next to your question there is a tag for "Mac OS" which probably was added automatically when you posted. Most browsers indicate the OS when making requests, but you can override that if you want to be a Windows person on the internet. ;-)

In Firefox 85 or 86, depending on when it's finished, Firefox for Windows will have a new print experience more similar to other browsers, including a built-in option to print to PDF.

That won't be a full-featured PDF -- any PDF generating through printing usually lacks clickable links unless the entire URL is shown -- but it will mean that you don't have to trust an add-on for this basic functionality. I posted a review of many PDF creation add-ons last Summer and the results were disappointing: https://www.jeffersonscher.com/ext/pdf-converters.html

Haha, this explains things. I agree, this is quite disappointing for such an important feature. Also, I believe I am not the only one to not install just any add-on for some small feature - I rather use the browser which has all the basic features.