how to remove scrollbars using javscript

//Hides scrollbars but does not allow scrolling
body {
  overflow-y: hidden; /* Hide vertical scrollbar */
  overflow-x: hidden; /* Hide horizontal scrollbar */
}

//Hides scrollbars but keep the ability to scroll
/* Hide scrollbar for Chrome, Safari and Opera */
.example::-webkit-scrollbar {
  display: none;
}

/* Hide scrollbar for IE, Edge and Firefox */
.example {
  -ms-overflow-style: none;  /* IE and Edge */
  scrollbar-width: none;  /* Firefox */
}

body {
  overflow-y: hidden; /* Hide vertical scrollbar */
  overflow-x: hidden; /* Hide horizontal scrollbar */
}

var button = document.getElementById('slide');
button.onclick = function () {
    var container = document.getElementById('container');
    sideScroll(container,'right',25,100,10);
};

var back = document.getElementById('slideBack');
back.onclick = function () {
    var container = document.getElementById('container');
    sideScroll(container,'left',25,100,10);
};

function sideScroll(element,direction,speed,distance,step){
    scrollAmount = 0;
    var slideTimer = setInterval(function(){
        if(direction == 'left'){
            element.scrollLeft -= step;
        } else {
            element.scrollLeft += step;
        }
        scrollAmount += step;
        if(scrollAmount >= distance){
            window.clearInterval(slideTimer);
        }
    }, speed);
}

function HideScrollbar() {
  var style = document.createElement("style");
  style.innerHTML = `body::-webkit-scrollbar {display: none;}`;
  document.head.appendChild(style);
}