How to use rasa CollectionDispather to send video as response?

Question

I tried below code blocks to show videos :

dispatcher.utter_message(attachment = "https://www.youtube.com/embed/-F6h43DRpcU")
dispatcher.utter_message(video = "https://www.youtube.com/embed/-F6h43DRpcU")
dispatcher.utter_attachment(attachment = "https://www.youtube.com/embed/-F6h43DRpcU")

dispatcher.utter_attachment(attachment={
              "type": "video",
              "payload": {
                  "title": "Watch Below Video",
                  "src": "https://www.youtube.com/embed/-F6h43DRpcU"
              }
            })

but none of these worked.

what is correct format to get video as a response in rasa chat?