1. To setup a product video you need to convert video to APNG using website https://ezgif.com/video-to-apng
   
   
2. Rename converted png with product name at start add video- . like below example.
   
   Product name: tulle midi dress
   Video name: video-tulle-midi-dress.png
   
   upload animated product image at image manager.
   
   
3. then add name – video tulle midi dress

Video Guide