Change video source script doesn't work, code changes but view does not

I am trying to build a dynamic webpage and having a issue about changing the playing video. I want to put a button and when user clicks on it, video should change. I am trying to use changing video source by a script. When i inspect, it changes the value of src href but it does not effect the view. Still old video plays. What should i change to make it work?

Here is my code:

<div id="source_change" class="source">CHANGE SOURCE</div>

<video style="position: relative; left: -47px; border-radius: 45px;" autoplay="autoplay" loop="loop" muted="" width="642" height="324"><source id="source_video" src="firstvideo.mp4" type="video/mp4" />
</video>

<script>
  document.getElementById('source_change').addEventListener('click', function() {
  document.getElementById('source_video').src = 'secondvideo.mp4';
  });
</script>

You need to set the ID on the <video> tag itself.
You might also need to do a load() afterwards to init the new source.

Try having a code setup like this:

<div id="source_change" class="source">CHANGE SOURCE</div>

<video  id="source_video" 
        style="position: relative; left: -47px; border-radius: 45px;" 
        autoplay="autoplay" loop="loop" muted="" width="642" height="324">
        
<source src="firstvideo.mp4" type="video/mp4" />
</video>

<script>

let myBtn = document.getElementById('source_change')
let myVid = document.getElementById('source_video');

myBtn.addEventListener('click', on_BtnClick );
  
function on_BtnClick ()
{
    myVid.src = 'secondvideo.mp4';
    myVid.load();
}

</script>