To install Flatpak on Solus, simply run:sudo eopkg install flatpak
Add the Flathub repository
Flathub is the best place to get Flatpak apps. To enable it, download and install the Flathub repository file or run the following in a terminal:flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
To complete setup, restart your system. Now all you have to do is install some apps!
Note: graphical installation of Flatpak apps is not yet possible with Solus, but will be available in the near future.