These steps assume you have already uploaded your video to Youtube.
Two main options
- Within Fusion Builder insert the Lightbox Element
- Set Content Type as Video
- Specify the Video URL in the format https://www.youtube.com/watch?v=xxxxxxxxx
- Upload a thumbnail image – recommend retrieving from youtube using the tool at http://www.get-youtube-thumbnail.com
- Embed direct on your page using the Fusion Builder Youtube Element
- Enter the video ID retrieved from the video url. If the video URL is https://www.youtube.com/watch?v=569TlvRLn90 then the video ID is 569TlvRLn90