Flatpak is a relatively new way of managing Linux packages. The basic commands of Flatpak are given below.
To list flatpaks, use the below command in a terminal window:
$ sudo flatpak list <enter>
It will display the following output:
Name Application ID Version Branch Installation
Mint-Y Gtk Theme org.gtk.Gtk3theme.Mint-Y 3.22 system
Mint-Y-Aqua Gtk The… org.gtk.Gtk3theme.Mint-Y-Aqua 3.22 system
To display the help for the flatpak command, enter:
sudo flatpak --help <enter>
To remove flatpak package:
$ sudo flatpak uninstall org.gtk.Gtk3theme.Mint-Y <enter>
Removes the flatpak named org.gtk.Gtk3theme.Mint-Y.
To install flatpaks, for example, Discord, in Linux Mint, start up Software Manager and it will show that Discord is available in Linux Mint as a flatpak package as shown in image below.