I would like to offer a way to get better 'save as' windows and more in Firefox while using Plasma.
First you must have these packages:
Then to test run using the
GTK_USE_PORTAL=1 environment variable like so:
If you are happy you could edit the .desktop file. But this might be overridden by subsequent updates.
So instead we will copy the .desktop file to our home directory and modify that.
Copy the original:
cp /usr/share/applications/firefox.desktop ~/.local/share/applications/
Modify the local version (use any editor you like):
Edit on the Exec lines this way:
Exec=/usr/bin/sh -c "GTK_USE_PORTAL=1 /usr/lib/firefox/firefox %u"
Exec=/usr/bin/sh -c "GTK_USE_PORTAL=1 /usr/lib/firefox/firefox --new-window %u"
Exec=/usr/bin/sh -c "GTK_USE_PORTAL=1 /usr/lib/firefox/firefox --private-window %u"
Save and enjoy your firefox/plasma integration
Notes and Extras
For further KDE integration have a look at the firefox addon
If you absolutely need appmenu patches there is
firefox-appmenu from the AUR