JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
</head>
<body>
<h2>This is a heading</h2>
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
<button>Click me</button>
</body>
</html>

JavaScript

function test1(){
  alert("Proba");
};
$(document).ready(function(){
  $("button").click(test1);
});