To automatically launch a video in a Shortways content, insert the video in the content,then switch to 'code' view </>, then, according to the video's type :
1 - If the video is a mp4 file : add the tag autoplay="true" in the video's parameters
<video class="embedded-video" width="100%" autoplay="true" src="https://videos.shortways.com/" etc.>
2 - if the video is from YouTube or DailyMotion : add ?autoplay=1 (or &autoplay=1 if the question mark is already there) in the link toward the video source
<iframe src="//www.youtube.com/embed/SRhh_c-M8Po?autoplay=1" width="320" height="180" etc."></iframe>