Adds media items to a specified product, either via URL or existing media ID.
NOTE: The URL is not validated and no event is triggered to indicate if the media was added successfully.
You can only call this method when authenticated as a Wix app or Wix user identity.
Product ID.
Sources of media items already uploaded to the Wix site.
This method doesn’t return any custom errors, but may return standard errors. Learn more about standard Wix errors.