Follow these simple steps to start using Flatpak
To install Flatpak, run the following in a terminal:
$ su
# inary it flatpak
$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
# flatpak remote-add --if-not-exists ramatak https://download.ramatak.com/ramatak.flatpakrepo
Note: graphical installation of Flatpak apps may not be possible with SulinOS.
To complete setup, return to the download page, and follow the instructions.!