Install Flatpak local on pop os

Install Flatpak
To install Flatpak on Pop!_OS 19.10 and earlier, simply run:
 sudo apt install flatpak
Add the Flathub repository
Flathub is the best place to get Flatpak apps. To enable it, run:
 flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
Restart
To complete setup, restart your system. Now all you have to do is install some apps!
Note: graphical installation of Flatpak apps may not be possible with Pop!_OS 19.10 and earlier.