JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>

</head>
<body>
<div id="container">

</div>
<button id="btn">
  Click me to change the dynamical div
</button>
</body>
</html>

JavaScript

$("#container").append("<div id='testdiv'>Dynamical Text</div>");

//both worked !
//$("#container").find("#testdiv").html("Hello world");

$("#btn").click(function(e){
	$("#container").find("#testdiv").html("Hello world");
});