Hello, found this in the FAQ section of the site earlier as I was also having the same problem... :))

Q: How do I add video to my profile or story?
A: If you are trying to add video from YouTube, look for a button on the video labeled <Embed>. Clicking that button will then show the code that you will need to copy and paste to either your profile or story body. Make sure you are not using the old embed code ("Use old embed code" must be unchecked). If using a different video service, look for anything that says "Embed" and use that code to add the video to your story or profile.

i really don't know