Howto debian12

enable flatpak:

sudo apt update && apt sudo -y instal flatpak

configure gnome software flatpak plugin:

sudo -y apt install gnome-software-plugin-flatpak

enable flatpak repo:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

more on flatpak commands:

https://wiki.vidalinux.org/index.php/Howto_flatpak