onderaan het bestand

/**
 * AJAX handler voor toggle bezorgmethode
 */
add_action('wp_ajax_set_delivery_method', 'set_delivery_method');
add_action('wp_ajax_nopriv_set_delivery_method', 'set_delivery_method');

function set_delivery_method() {
    if (!isset($_POST['method'])) {
        wp_send_json_error('Geen methode ontvangen');
    }

    $method = sanitize_text_field($_POST['method']);

    // Zet een cookie voor 1 dag
    setcookie('delivery_method', $method, time() + DAY_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN);

    wp_send_json_success("Methode ingesteld op: $method");
}

/**
 * Script en AJAX-variabelen insluiten
 */
add_action('wp_enqueue_scripts', function () {
    wp_enqueue_script(
        'delivery-toggle',
        get_stylesheet_directory_uri() . '/js/script.js',
        ['jquery'],
        null,
        true
    );

    wp_localize_script('delivery-toggle', 'deliveryAjax', [
        'ajaxurl' => admin_url('admin-ajax.php'),
        'nonce'   => wp_create_nonce('delivery_nonce')
    ]);
});<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/pizzaeataliano/public_html/wp-content/themes/order_v1/functions.php:148) in <b>/home/pizzaeataliano/public_html/wp-includes/pluggable.php</b> on line <b>1450</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/pizzaeataliano/public_html/wp-content/themes/order_v1/functions.php:148) in <b>/home/pizzaeataliano/public_html/wp-includes/pluggable.php</b> on line <b>1453</b><br />