public function rider_register_shortcode() {
    ob_start(); ?>

    <div class="tn-rider-form-wrap">
        <h2>🏍️ TasteNaija Rider Registration</h2>
        <p class="tn-rider-intro">Fill your correct details to join TasteNaija delivery riders.</p>

        <form method="post" action="https://tastenaija.com/wp-admin/admin-post.php">