how to add progress bar in blogger

<div class='progress-container'>
<div class='progress-bar' id='myBar' style="width:0%;"></div>
</div>

<style>
.progress-container{width:100%;position:fixed;z-index:99;top:0;left:0;}
.progress-bar{height:5px;background:#F86152;}
</style>

<script>
window.onscroll = function() {
    myFunction()
};
function myFunction(){
    var winScroll = document.body.scrollTop || document.documentElement.scrollTop;
    var height = document.documentElement.scrollHeight - document.documentElement.clientHeight;
    var scrolled = (winScroll / height) * 100;
    document.getElementById("myBar").style.width = scrolled + "%";
}
</script>