Bulk update product variations weight

I've created a module for a custom VBO action. The action can be selected in the view, and the function is executed, but $request is empty and the selected product variation IDs are not available.

class VariationWeightSet extends ViewsBulkOperationsActionBase implements PluginFormInterface {

  use StringTranslationTrait;

  /**
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
    $request = \Drupal::request();
    $storage = \Drupal::service('entity_type.manager')->getStorage('commerce_product_variation');

    if ($ids = explode('|', $request->query->get('ids'))) {
      $variations = $storage->loadMultiple($ids);
      $form_state->set('variations', array_values($variations));
      $variation = end($variations);
      $weight = $variation->getWeight()->toArray();
      $form['warning'] = [
        '#markup' => new TranslatableMarkup('<h1>Set new Weight for <span style="color:red">@count</span> variations</h1>', ['@count' => count($variations)]),
      ];
      $form['weight'] = [
        '#type' => 'container',
        '#attributes' => ['class' => ['container-inline']],
      ];
    }
    return $form;
  }

}

How can I get the selected product variation IDs?