David Kimura PRO said over 2 years ago on Streaming Videos with Active Storage :
You wouldn't be able to use the connect(), initialize(), and disconnect() as those are functions for stimulus. Since your ID attribute of your video player is my-video then you would need to change the selector to document.getElementById('my-video') 

So it should look something more like this.

import videojs from 'video.js'
import 'video.js/dist/video-js.css'

$(document).on('turbolinks:load', function(){
  let videoPlayer = videojs(document.getElementById('my-video'), {
    controls: true,
    playbackRates: [0.5, 1, 2],
    autoplay: false,
    fluid: true