Need help with running firefox on the nvidia card

i have a laptop and use optimus manager(intel/nvidia) and currently in hybrid mode.
i have the proprietary drivers installed.
i use Manjaro(arch based)distribution.

i tried all kind of settings to make Firefox use Nvidia,but it never shows in nvidia-smi .

this is what i tried with no success:

-simply do prime-run Firefox( prime-run glxgears does appear in nvidia-smi)

-copy the firefox.desktop file from /usr/share/applications/ and put it in ~/.local/share/applications/
then edit it with either:

Exec=/usr/bin/prime-run /usr/lib/firefox/firefox %u
Exec=prime-run /usr/lib/firefox/firefox %u 

-i also tried updating the desktop file like it’s shown in the Arch wiki with
update-desktop-database ~/.local/share/applications

-tried renaming the firefox.desktop file to firefoxnvidia and also change the Name= inside the file.

in about:config i have layers.acceleration.force-enabled to true and gfx.webrender.all to true

i looked all around and the only things i didn’t try were to start Firefox with MOZ_X11_EGL=1or MOZ_WEBRENDER=1 or both?
and change to true



IIRC, this doesn’t work due to a bug in Firefox. Chrome had the same issue, which was fixed meanwhile. Search the forum, there was a thread about it.