Most Beat Saber mod installers weren't built to run on Linux, so we have to do some small things to get it to work on Linux. It is very similar to a Windows install, but you will need some workarounds.
Using mods in Linux isn't supported by mod developers, so you might encounter bugs!
Wine doesn't use DLLs the same way Windows does, so you have to change a few things to make the IPA injection work.
Messing with registry files can be dangerous, make sure you don't touch anything besides what the guide tells you to. If you messed up the registry file, either verify your game files or reinstall Beat Saber after backing up your files.
Navigate to /.local/share/Steam/steamapps/compatdata/620980/pfx/ and open user.reg
Inside the file, navigate to [Software\\Wine\\DllOverrides]. Try Ctrl + F and type DllOverrides to get there more quickly
Paste "winhttp"="native,builtin" on the bottom below the others, and save the file.