Using Javascript to make a video player [closed]

I am using Javascript to make a video player that plays a video. All the codes seem to be added right. But the code does not seem to work. Here it is:

HTML

<video  id="myVideo">
    <source src="coolfirst2hours.mp4" type="video/mp4">
  </video>
<button id="playVid" type="button">PLAY</button>

Javascript

// Get the video and play button elements
const videoElem = document.getElementById('myVideo');
const playButton = document.getElementById('playVid');

// Add event listener to play button
playButton.addEventListener('click', () => {
  videoElem.play();
});