Thank you for writing up this tutorial - it was very helpful!
One thing I found: after following the tip about importing the API key via the `api_key.env` file, I found communication with SilentWolf wasn't working in my exported version of the game. The solution, I found, was to ensure that the Project > Export > Resources included `*.env` files under the "Filters to export non-resource files/folders" section (see https://godotengine.org/qa/91714/file-read-and-write-worked-from-godot-console-w...)
Anyway, just wanted to share that. Thanks again!