I have a similar problem with YouTube API, that have been answered here, but even if I request data with start date when I uploaded the video, I receive only headers.
Can you describe me some criteria which YouTube video must have to provide data about audienceRetention metric, because if I go to YouTube Analytics , some data from this metric are there.
In docs, there's something about video length and play count, but no specific information.
Can you please explain why some videos don't have these data, yet?