<video id="videoPlayer" controls>
  <source src="sample-video.mp4" type="video/mp4">
</video>
<progress id="progressBar" value="0" max="100"></progress>

<script>
  var videoPlayer = document.getElementById("videoPlayer");
  var progressBar = document.getElementById("progressBar");

  videoPlayer.ontimeupdate = function() {
    var percentage = (videoPlayer.currentTime / videoPlayer.duration) * 100;
    progressBar.value = percentage;
  };
</script>