Can I in Firefox to select font I need ?

[petrogromovo]

Hello,
If Firefox 81.0.2 under Kubuntu 18 I want to set DejaVu Sans
font (In the system Settings I also use this font) and I opened about:preferences page
i tried to set it anywhere : https://imgur.com/a/viY1tLN
but in thge first proportional Selection I do not have the font I need
and looks like the rest of fonts are not applied.
I check it on different pages , including https://ubuntuforums.org

Can I make these options to work?

Thanks!

[Impavidus]

I know this doesn't sound like a very helpful response, but your package manager should have upgraded you to Firefox 83. If you're still on 81, there could be a problem with your package management.

[petrogromovo]

Does problem with your package management influence fonts I see in firefox ?

[CelticWarrior]

No, the problem is with your package management, not theirs, and no, being in an older version is unrelated to fonts.

[Impavidus]

That's why I wrote that my response wasn't very helpful. Your settings, disallowing sites to choose their own font, should work. They work on my Firefox 83. It's not a spectacular feature with a lot of active development, so I think it should work on every release of Firefox. But to find out what's wrong, one has to start somewhere.

[SeijiSensei]

I'm using Firefox 83.0 on Kubuntu 20.04. When I go to the general preferences page, I can set the font to DejaVu Sans, and the font changed on an index page.

Remember most web pages will use their own fonts via CSS and not rely on the default.