JSFiddle - React, Tailwind, and code Playground

HTML

<p>Plese click on scrollbar</p>

CSS

body {
    height: 3000px;
}

JavaScript

// function for scrollbar click detection
var clickedOnScrollbar = function(mouseX){
  if( $(window).outerWidth() <= mouseX ){
    return true;
  }
}

// detect click for mousedown event
$(document).mousedown(function(e){
  if( clickedOnScrollbar(e.clientX) ){
    alert("clicked on scrollbar");
  }
});