login.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="style.css" />
    <title>Document</title>
  </head>
  <body>
    <form method="POST" action='/login'>
      <input type="form" placeholder="username" id="username"></input>
      <input type="form" placeholder="password" id="password"></input>
      <button id="submitBtn" value="login">Login</button>
    </form>
    <script src="login.js"></script>
  </body>
</html>