Can I add this to an existing godot install?

I am new to how GDExtension works, and was wondering can this be added to an already installed version of Godot? I got my version from the Steam store. Can I add this extension to that or do I have to install the one that is in the releases?

Start by checking the GDExtension requirements against the Steam-installed Godot version and the project's releases. Done means documenting whether the Steam installation is supported and, if so, how to add the extension; otherwise, state that the release installation is required.

Written by the indexing model from the issue text.