private function getCategories($campaignId) {
    $categories = [];

    /** @var \Drupal\node\Entity\Node $campaign */
    $campaign = $this->entityTypeManager->getStorage('taxonomy_vocabulary')->load($campaignId);

    /** @var \Drupal\taxonomy\Entity\Vocabulary $vocabulary */
    $vocabulary = $campaign->field_campaign_fitness_category->entity;
    /** @var \Drupal\taxonomy\VocabularyStorageInterface $vocabularyStorage */
    $vocabularyStorage = $this->entityTypeManager->getStorage('taxonomy_vocabulary');
    $tids = $vocabularyStorage->getToplevelTids([$vocabulary->id()]);

    $terms = $this->taxonomyStorage->loadMultiple($tids);
    /** @var \Drupal\taxonomy\Entity\Term $term */
    foreach ($terms as $term) {
      $categories[$term->id()] = $term->getName();
    }
    return $categories;
  }