Sorry I have never used this great option , and I can only offer you eBay's information as to how to load a video onto your listing.
You can only add one video per listing, but you can use the same video on multiple listings - you just need to upload it once. Upload a video using the new listing tool by selecting Add video from the Photos & Video section: - The video should be .mp4 or .mov with a 150MB limit, or about one minute long - The new listing tool is currently only available to Seller Hub users, but all users will have access eventually https://www.ebay.com/help/selling/listings/creating-managing-listings/add-video-to-listing?id=5272
If the above is not helpful, apologies, and hopefully someone who has managed this feature will come along and help.
@jimandjan0506
