In order to set a video to autoplay,follow these steps:

  1. Navigate to onMessage > Website > [Site name] > Pages & Menu's
  2. On the page the video is located on, click the Wrench and select Edit Page Content
  3. On the videos block, click the Cogwheel to edit the block settings User-added image
  4. From the Settings dialog, mark the box next to AutoplayUser-added image
  5. Click Save
  6. Click Apply Changes in the bottom right for the page