How do I make this scrollbar focus on the bottom of this div. Does JavaScript is necessary?

How do I make this scrollbar focus on the bottom of this div. Does JavaScript is necessary?

You can try this:
var objDiv = document.getElementById("your_div");
objDiv.scrollTop = objDiv.scrollHeight;
$("divname").animate({ scrollTop: $('divname').prop("scrollHeight")}, 0);
Does require Jquery
nice and simple just put this code somewhere in your script, preferably the top
<script>
var objDiv = document.getElementById("chatbox");
if ( window.history.replaceState ) {
objDiv.scrollTop = objDiv.scrollHeight;
window.history.replaceState( null, null,
window.location.href );
}
</script>
You can use Element.scrollIntoView()
Example:
document.getElementById('your_div').scrollIntoView()
Demo:
document.getElementById("my_div").scrollIntoView();
.page-body {
overflow: auto;
max-height: 200px;
}
<div class="page-body">
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p>lorem ipsum</p>
<p id="my_div">lorem ipsum</p>
</div>