Associating File Types with a Unity App

Simple enough question, is it possible to associate a file type with a Unity app so that file type will open with said app, then have the app decide what to do with the file via a script?

Hi,
this is what I’m trying to do with my Unity app. I have a json file, with my own extension, containing some scene configuration. I want to double click on it, so my app starts the file content can be deserialized and my game objects configured on the fly. I associated the file extension with my Unity built app by double clicking on it and then choosing “open with”.
To check if it works I set this in the Start:

void Start()
{
var arguments = Environment.GetCommandLineArgs();
outputText.text = $“GetCommandLineArgs: {String.Join(”, “, arguments)}”;
}

But seems that no argument is passed. So I don’t know how to access the file.
Does anyone has some tips?
Thank you