on about
:config there are four or five "xdg" related options. As the wonderful Arch-linux wiki explains:
Quote:
Each setting can have the following values:
0 – Never
1 – Always
2 – Auto (typically depends on whether Firefox is run from within Flatpak or whether the GDK_DEBUG=portals environment is set)
The settings are:
widget.use-xdg-desktop-portal.file-picker – Whether to use XDG portal for the file picker
...