I'm new to the Linux community and I decided to start with Zorin OS. I don't usually play online games but every now and then I play something on Steam. I formatted my HD in EXT4 and when I went to select it as the main storage source on Steam it simply isn't recognized and I honestly don't know what to do.
Using the heroic games launcher I was able to install and play normally, but Steam does not recognize the HD and I did not find anything in my searches.
Have you installed Steam as a flatpak? If so, you should give the program the necessary access rights so that it can access your hard disk. You can do this by installing flatseal and then setting the permissions for Steam accordingly.
Otherwise, it is also important that your hard disk is mounted. You can do this via gnome-disks.
You can also use the apt package from Steam (Zorin package), this is recommended. There are fewer problems and you do not need an extra program to grant access rights. Before installing it remove the flatpak version.
Aye, Zorin Package (.deb) is preferable as @Forpli mentioned. Flatpak and Snaps packages are running in Sandbox and need some extra steps to work properly. That's why Zorin package (it's actual .deb package) is favor among us. 
Thank you very much, it was actually because I was using flatpak instead of .deb like you said, thank you very much. 
Thanks for the help too!
