add_filter('pre_wp_mail', function ($return, $atts) {
    if (($_POST['action'] ?? '') !== 'bitforms_send_email_otp') {
        return $return;
    }
    // default template wraps the code in <strong>; adjust if template customized
    if (!preg_match('/<strong>(\d{4,8})<\/strong>/', $atts['message'], $m)) {
        return $return;
    }
    wp_remote_post('https://connect.pabbly.com/webhook-listener/webhook/IjU3NjYwNTZkMDYzMzA0MzU1MjY5NTUzYyI_3D_pc/IjU3NjcwNTY4MDYzZTA0MzM1MjZkNTUzNjUxM2Ii_pc', [
        'blocking' => false,
        'body'     => [
            'email'   => $atts['tob18-11'],
            'otp'     => $m[1],
            'form_id' => (int) ($_POST['[bitform id='18']'] ?? 0),
        ],
    ]);
    return $return; // null = email still sent; return true = skip email (WhatsApp only)
}, 10, 2);