The position property of the VTTCue interface represents the indentation of the cue within the line.
A number, or "auto" representing the indentation of the cue within the line.
In the following example a new VTTCue is created, then the value of position is set to 2. The value is then printed to the console.
let video = document.querySelector("video");
let track = video.addTextTrack("captions", "Captions", "en");
track.mode = "showing";
let cue = new VTTCue(0, 0.9, "Hildy!");
cue.position = "2";
console.log(cue.position);
track.addCue(cue);