<!--html-->

<video id="myVideo" width="x" height="x" controls>
<source src="URL_TO_YOUR_VIDEO.mp4" type="video/mp4">
Your browser does not support the video tag.
</video>

<!--html end-->

<!--Javascript-->

<script>
document.addEventListener('DOMContentLoaded', function() {
var video = document.getElementById('myVideo');
video.volume = 0.5; // Set the volume to 50%
});
</script>

<!--Javascript end-->