This issue arose while planning to add YouTube's new 'Test & Compare' feature, which was announced last June, to our project.
I recently learned that YouTube has released a feature called "Test & Compare" for A/B testing, which allows uploading up to three thumbnails. I am looking for a related API for this feature.
I couldn't find any documentation about a "Test & Compare" API on the official YouTube API documentation. I have carefully read the youtube official documentation. My main question is whether there is any API available that allows uploading multiple thumbnails for a single video on YouTube. Is there an API I might have missed that supports this functionality?