end.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Congrats!</title>
    <link rel="stylesheet" href="app.css">
</head>

<body>
    <div class="container">
        <div id="end" class="flex-center flex-column">
            <h1 id="finalScore"></h1>
            <form>
                <input type="text" name="username" id="username" placeholder="username" />
                <button type="submit" class="btn" id="saveScoreBtn" 
                onclick="saveHighScore(event)" disabled>Save
                </button>
            </form>
            <a class="btn" href="/game.html">Play Again</a>
            <a class="btn" href="/">Go Home</a>
        </div>
    </div>
    <script src="end.js"></script>
</body>

</html>