11 months ago - prismaticmarcus - Direct link
Moved to Tech Support  
11 months ago - AndrewT - Direct link
Launcher 2023.14 had a bug where it did not work on Linux. That bug is long fixed, the current version is 2024.2 . What launcher version are you on now?

Note that we do not support Proton or other emulations, just native Linux.

And Steam must be their native client as seen here
store.steampowered.com

Steam, The Ultimate Online Game Platform

Steam is the ultimate destination for playing, discussing, and creating games. store.steampowered.com store.steampowered.com "Install Steam Now"
not Flatpack or any other such installation of it.