Thread: What is wrong with my code

Hi, I am a beginner at Java and was simply making some controls. However whenever i try and open in chrome i get an error in the console saying "Uncaught TypeError: Cannot read property 'addEventListener' of null
at HTMLDocument.initialiseWebPage (VideoScript.js:26)" pointing to this line

 playButton.addEventListener ( "click", PlayPause );

. Thanks for your help in advance

document.addEventListener('DOMContentLoaded', initialiseWebPage);
///explanation
 
function initialiseWebPage()
{
	const myVideo = document.querySelector ( "video" );
	myVideo.removeAttribute( "controls" );
	const playButton = document.getElementById ("playPause");
 
 
	function PlayPause()
	{
		if (myVideo.paused === true)
		{
			myVideo.play();
			//
			playButton.innerHTML = "Pause";
		}
		else
		{
			myVideo.pause();
		playButton.innerHTML = "Play";
		}
	}
	playButton.addEventListener ( "click", PlayPause );
}