The method was tested on desktop and ankidroid.
It is necessary to have two fields for one video.
One is used in the template. The second is necessary so that ANKI does not delete the video.
{{Video}} = name.webm
{{Video Sound}} = [sound:name.webm]
In the template:
<video src="{{Video}}" playsinline autoplay onclick="this.currentTime=0;this.play()"></video>