This comes up sometimes so I figured I would cover it. However, as you can notice by scanning the page, it is short and sweet. When exporting for OSX, there are a few minor modifications you must make to the app's ZIP file.
There is, by default, a Godot Engine icon already inside the
You should be able to create it online or with a Photoshop plug-in. Unfortunately I don't have any great resources or links for this at the time of writing, but a quick DuckDuckGo search should sort you out.
Second, you need to add the following to the
Alternatively, if you are using the pre-compiled one from GodotSteam's Github release section, you can thank SapphireMH for already including this file for you!
The steam_appid.txt file should contain your game's Steam App ID. As per usual, this file is only required if you are running the game outside of the Steam client. So if this is the app zip you are shipping, then feel free to leave it out. The file is only needed for external testing.
And that's about that for Mac exporting.