Drupal → AJAX в форме корзины Commerce 2

use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\ReplaceCommand;
use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
use Drupal\Core\EventSubscriber\MainContentViewSubscriber;
use Drupal\Core\Form\FormBuilderInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Messenger\MessengerInterface;
use Drupal\Core\Render\Element;
use Drupal\Core\Url;

/**
 * Implements hook_form_FORM_ID_alter(): views_form_commerce_cart_form_default.
 */
function MODULENAME_form_views_form_commerce_cart_form_default_alter(array &$form, FormStateInterface $form_state): void {
  // AJAXify "update" button
  $form['#action'] = Url::fromRoute('commerce_cart.page')->toString();
  $form['actions']['submit']['#ajax'] = [
    'callback' => 'MODULENAME_ajax_update_cart_form',
    'event' => 'click',
  ];
  $form['actions']['submit']['#attributes']['class'][] = 'js-hide';

  // AJAXify "quantity" inputs
  $form['actions']['submit']['#name'] = 'update';
  foreach (Element::children($form['edit_quantity']) as $key) {
    $form['edit_quantity'][$key]['#ajax'] = [
      'event' => 'change',
      'callback' => '',
      'trigger_as' => [
        'name' => 'update',
      ],
    ];
  }

  // AJAXify "delete" buttons
  foreach (Element::children($form['remove_button']) as $key) {
    $form['remove_button'][$key]['#ajax'] = [
      'callback' => 'MODULENAME_ajax_update_cart_form',
      'event' => 'click',
    ];
  }
}

/**
 * AJAX update cart page.
 */
function MODULENAME_ajax_update_cart_form(array &$form, FormStateInterface $form_state): AjaxResponse {
  // Delete status messages
  \Drupal::messenger()->deleteByType(MessengerInterface::TYPE_STATUS);

  // Create fake request to cart page
  $fake_request = \Drupal::request()->duplicate();
  $fake_request->query->replace(UrlHelper::filterQueryParameters($fake_request->query->all(), [
    FormBuilderInterface::AJAX_FORM_REQUEST,
    AjaxResponseSubscriber::AJAX_REQUEST_PARAMETER,
    MainContentViewSubscriber::WRAPPER_FORMAT,
  ]));
  $fake_request->request->replace([]);
  \Drupal::requestStack()->push($fake_request);

  // Get cart page content
  $cart_page_content = \Drupal::service('controller_resolver')->getController($fake_request)();

  // Update cart page content in browser
  $response = new AjaxResponse();
  $response->addCommand(new ReplaceCommand('.cart-form', $cart_page_content));

  // Remove fake request
  \Drupal::requestStack()->pop();

  return $response;
}

Из комментариев должно быть всё понятно.