You can see the example of video background from the :
1. Open the page which you want in edit content mode
2. Click on the plus button on the bottom left corner of the screen and open the Element panel.
3. Choose a row shortcode from the left sidebar
4. Open the background tab on the top of the row.
5 – Choose “video” from the row background
6 – Video options :
Webm file URL: add a link to a video file which ends with a .webm
MP4 file URL: add a link to a video file which ends with a .mp4
Video Preview Image: this image will be shown when the video is not playable for any reason.
Also, small devices don’t support background video and the video preview image will be shown instead.
Choose a video link from your website host not from the other sites.
It’s recommended to use both wbem and mp4 files in case the user browser does not support one it will play the other format.