<html lang="en">
<head>
    <title>Hello {{hello}}!</title>
</head>
<body>
<h1>Hello {{hello}}!</h1>
<form action="{{ url_for('hello.hello') }}" method="POST" enctype="multipart/form-data">
    <label for="world">Your name </label><input type="text" name="world" id="world"/>
    <input type="submit" value="Submit"/>
</form>
</body>
</html>