From the docs of Codium.

In MacOS/Windows, go to VisualStudioCode and type CMD/crtl + p, then > and search for "Shell Command: Install 'codium' command in PATH", it will prompt for authorization to configure it within your system, authorize it and you're done.

Unfortunately, this does nothing for me... when I search for "shell..." VSCodium shows "no commands found"

I can't find any help for this problem anywhere, so I think I'll have to reinstall and cross my fingers.