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

  1. Navigate to onMessage > Website > [Site name] > Pages & Menus
  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