clone iinuwa/xdg-desktop-portal to where you store your git repos.
I use ~/git
To build it i used a distrobox, you can find the instructions here: xdg-desktop-portal/docs
When it is build, you can replace the running deamon with the --replace flag.
export XDG_DESKTOP_PORTAL_ENABLE_EXPERIMENTAL=credential
~/git/xdg-desktop-portal/_build/src/xdg-desktop-portal --replace