What is Live Link Protocol?

I want to create a motion capture tool that sends data to Unreal Engine.

And I think it’s best to use the Live Link feature for that.

However, there is not much information about Live Link yet.

When I open the “Live Link Face” app on iOS, there is an item in the app to select the version of “Live Link Protocol”.

Perhaps the “Live Link Face” app is sending data using the “Live Link Protocol”.

However, when I searched for “Live Link Protocol” using Google, I couldn’t find any information.

If anyone knows more about “Live Link Protocol”, please let me know.