<!DOCTYPE html>
<html lang="en">
    <body>
        <h1>First-Time OTP Setup</h1>
        <p>Scan this QR code with your OTP app (e.g., Google Authenticator):</p>
        ${img_str}
        <p>Then use the OTP to log in.</p>
        <a href="login">Go to Login</a>
    </body>
</html>