JSFiddle - React, Tailwind, and code Playground

HTML

<div>Non main content</div>

<div id="main_content">Main content</div>

JavaScript

$(document).ready(function(){
        $("#main_content").keydown(function(e) {
            if(e.which == 40) {
                alert("button Down");
                return false;
            }
        });
    });