JSFiddle - React, Tailwind, and code Playground

HTML

<button id="a">append</button>
<p>catched: <span id="catched">0</span> times</p>
<div id="looking"></div>

JavaScript

$("#looking").bind("DOMNodeInserted", function() {
    $("#catched").text(parseInt($("#catched").text()) + 1);
});
    
$("#a").click(function() {
    $("#looking").append("<div>appended</div>");
});