Follow these simple steps to start using Flatpak
A Flatpak package is available on SlackBuilds. To install it (assuming you use Sbopkg/sqg), first create the queuefile and run the following as root:
Then compile it. Load the queuefile, press 'Q', and wait:
Flathub is the best place to get Flatpak apps. To enable it, run:
To complete setup, restart your system. Now all you have to do is install apps!
Note: graphical installation of Flatpak apps may not be possible with Slackware.