如何在Bootstrap上滚动模式窗口？

Question

我有一个包含Drupal 8和Bootstrap 3的网站

我创建了一个自定义模块，以在模式窗口中显示页面。该页面包含很多文本，我希望它在模式窗口中具有滚动条。

我该怎么做？这是我的模块代码和我发现的信息：

https://getbootstrap.com/docs/4.3/components/modal/#scrolling-long-content

  

您还可以创建一个可滚动模态，允许滚动模态   在.modal-dialog中添加.modal-dialog-scrollable。

我什至不知道我的代码对Bootstrap是正确的还是可以改进的。

<?php

namespace Drupal\commerce_marketplace_terms_and_conditions\Plugin\Commerce\CheckoutPane;

use Drupal\Component\Serialization\Json;
use Drupal\Core\Form\FormStateInterface;
use Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane\CheckoutPaneBase;
use Drupal\commerce_checkout\Plugin\Commerce\CheckoutPane\CheckoutPaneInterface;
use Drupal\Core\Link;
use Drupal\Core\Url;

/**
 * Provides the completion message pane.
 *
 * @CommerceCheckoutPane(
 *   id = "marketplace_terms_and_conditions",
 *   label = @Translation("Marketplace Terms and Conditions"),
 *   default_step = "review",
 * )
 */
class MarketplaceTermsAndConditions extends CheckoutPaneBase implements CheckoutPaneInterface {

  /**
   * {@inheritdoc}
   */
  public function buildPaneForm(array $pane_form, FormStateInterface $form_state, array &$complete_form) {
    $store_name = $this->order->getStore()->getName();
    $store_id = $this->order->getStoreId();
    $pane_form['#attached']['library'][] = 'core/drupal.dialog.ajax';
    $attributes = [
      'attributes' => [
        'class' => 'use-ajax',
        'data-dialog-type' => 'modal',
        'data-dialog-options' => Json::encode([
          'width' => 'auto'
        ]),
      ],
    ];
    $link = Link::fromTextAndUrl(
      $this->t('terms and conditions of the store "@store_name"', ['@store_name' => $store_name]),
      Url::fromUri("internal:/store/$store_id/cgv", $attributes)
    )->toString();
    $pane_form['marketplace_terms_and_conditions'] = [
      '#type' => 'checkbox',
      '#default_value' => FALSE,
      '#title' => $this->t('I have read and accept @terms.', ['@terms' => $link]),
      '#required' => TRUE,
      '#weight' => $this->getWeight(),
    ];
    return $pane_form;
  }

}