flatpak install —user —from
https://flathub.org/repo/appstream/com.valvesoftware.Steam.flatpakref
Installing: com.valvesoftware.Steam/x86_64/stable
Required runtime for com.valvesoftware.Steam/x86_64/stable (org.freedesktop.Platform/x86_64/1.6) is not installed, searching...
The required runtime org.freedesktop.Platform/x86_64/1.6 was not found in a configured remote.
error: The Application com.valvesoftware.Steam/x86_64/stable requires the runtime org.freedesktop.Platform/x86_64/1.6 which is not installed