Flatpak support is built in from MX 18 and later. It is only required to activate the Flathub repository following these instructions:
Open MX Package Installer (open the menu and look in MX Tools), select the "Flatpaks" tab, to activate the repository you will need to enter the root password.
Start uw systeem opnieuw op om de installatie te voltooien. Nu hoeft u alleen nog maar apps te installeren!