My code does not work, please help. It is very simple, but does not know why. : This is a test code. It is suppose to show "How are you doing today? Buddy", but it does not show anything on the page right now and console does not say anything. Anyone knows why? Help please. Thank you.

    <!DOCTYPE html>
    <html>
    <head>
        <title>test</title>
        <script   src="http://code.jquery.com/jquery-3.3.1.min.js"   integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="   crossorigin="anonymous"></script>
    <script>
    function demo(){
    let newPara = window.document.createElement("p");
    newPara.innerHTML="<h1>How are you doing today? Buddy</h1>";
    document.body.append(newPara);
    }
    </script>
    </head>
    <body>
    
    <div onload="demo()">
    
    
    </div>
    
    
    
    </body>
    </html>

