How to Install Flatpak on Elementary OS 5

Installing

2. 2. Enabling Flatpak Repo

   Then to Add Flatpak Repository for Elementary OS
   Execute:

   sudo add-apt-repository ppa:alexlarsson/flatpak

   And then to Refresh Apt Repos Elementary OS:

   sudo apt update

   Authenticate with the User Admin Pass.
   If Got “User is Not in Sudoers file” then see: How to Enable sudo.

3. 3. Installing Flatpak

   Finally, to Install Flatpak for Elementary OS
   Simply play:

   sudo apt install flatpak