Document Dom

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Page Title</title>
</head>
<body>

   <h1>Welcome To CloseTag.com</h1>
   <button type="button" id="button">Try It</button>
    <script>
    let button = document.getElementById('button');
    button.addEventListener("click",()=>{
      document.title = "CloseTag";
    });
    </script>
  
</body>   
</html>