How to disable the read mode option of Edge/ Firefox browser for a website page.

In some browsers like Microsoft Edge and Firefox, there is a reading mode feature. This feature can be accessed by clicking the F9 key. So, to avoid read mode switching for a web page,

<script type="text/javascript">
	document.addEventListener("keydown", function(event) { 
		if (event.key === "F9") {
			event.preventDefault();
			
		}});
</script>