JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <link rel="stylesheet" href="test.css">
</head>

<body> 
    <p id="add2"></p>
    <script type="text/javascript" src="test.js"></script>
</body>
</html>

JavaScript

$(document).ready(function() {
    function add(a,b,c,d) {
        return a + b + c + d;
    }
    $('#add2').html(add(5,10,15,20));
});