Unable to install flatpak from flathub.org via the "Install" button (flatpakref not working)

[trusktr]

Steps to reproduce:

• visit https://flathub.org
• find a package, for example: https://flathub.org/apps/com.mastermindzh.tidal-hifi
• Click the Install button.
• This downloads a .flatpakref file.
• Open the file (some browsers have a direct "open" option that opens the file after temporarily downloading it, but you can also double click it in Gnome Files or similar).
• This causes the Add/Remove Software app to open, but nothing happens (or there's no indication that anything is happening).

I expected that opening the Installed (downloaded) file would cause the flatpak to be installed by Add/Remove Software (Pamac).

When Add/Remove Software opens, we end up on an empty view like the following, with no output, no loading animation, nothing happening:

[Boria138]

https://addons.mozilla.org/en-US/firefox/addon/flatline-flatpak/

[Boria138]

This is a limitation of flatpak it does not create appstream links, it just downloads the file, Firefox has this extension, I don't know about others

[viggy96]

It would be amazing if Pamac could open flatpakref files, it would greatly help less experienced users to install programs that are distributed as flatpak, but have yet to be published on Flathub (or some other remote).