bee_hotel-1.x-dev/modules/beehotel_samplehotel/beehotel_samplehotel.module

<?php

/**
 * @file
 * Sample Hotel - Install and configure for a Sample Hotel.
 */

/**
 * Implements hook_formatter_page_attachments().
 */
function beehotel_samplehotel_page_attachments(array &$page) {
  $path = \Drupal::service('path.current')->getPath();
  if ($path == "/admin/beehotel/vertical") {
    $page['#attached']['library'][] = 'beehotel_samplehotel/vertical';
  }
}