Found a solution. It seems 0.18.0 requires manual configuration and expects desktop environments to have their own portals.conf as explained in https://github.com/flatpak/xdg-desktop-portal/issues/1077#issuecomment-1688007044 The workaround is to add a custom config like https://github.com/flatpak/xdg-desktop-portal/issues/1077#issuecomment-1715896552 I use river and tested that. It worked.