templates/login.html

<!DOCTYPE html>
<html>
<head>
    <title>Login</title>
</head>
<body>
    <h2>Login</h2>
    <form method="POST">
        <label>Username:</label>
        <input type="text" name="username" required><br><br>

        <label>Password:</label>
        <input type="password" name="password" required><br><br>

        <label>
            <input type="checkbox" name="remember"> Remember Me
        </label><br><br>

        <button type="submit">Login</button>
    </form>
    <p>Don't have an account? <a href="{{ url_for('signup') }}">Signup here</a></p>
</body>
</html>