1. Add your .mp4 video as a RapidWeaver Resource, or host it on a server. For more information, see tutorial How to choose an autoplay video source.
2. Drag the Vast stack to the desired area to play on your stacks page.
3. Add a Poster placeholder image that will be shown before your video is loaded. This is optional, a video poster image is not required.
4. Click Video Source Set Link button, then either select your video under Resource, or enter the URL to your hosted video.
5. Disable the Vast Load toggle Stack.
6. Done ? Switch to Preview, your autoplay video should now be playing.