Hello, on F40 in order to be able to use Plasma file picker on Firefox and Thunderbird, we still have to setup the GTK_USE_PORTAL=1 environment variable, despite having widget.use-xdg-desktop-portal.file-picker = 2 setted and package xdg-desktop-portal-kde being installed. A friend of mine which is a KDE developer, he is using Arch and he does not need to have such variable to be set on his systems. Perhaps we somewhere have a packaging problem in Fedora?