Hi there, welcome to the forum.
Please always include your garuda-inxi as required by the template.
Please check this thread and the one linked therein.
It seems to be a known issue but there seems to be at least a workaround.
sudo pacman -S xdg-desktop-portal-kde
Open file ~/.firedragon/firedragon.overrides.cfg
Set lockPref("widget.use-xdg-desktop-portal.file-picker", 2)