Install Steam

All I did, was install the Flatpak version offered in the software store. Initially Steam launched ok, subsequent launches were app crashes. Someone on the forum taught me to create a desktop shortcut, that allows me to execute the program launch in terminal, which launches the GUI app without crash to desktop.

Double click the desktop icon, & I get this.

This is the contents of the file if your curious about what I did.

Now, in order for me to grant access to USB external drives for Steam, I had to also use Flatseal to do that as well.