code: public function checkAuthDictionaryPopulation($version)
      {
          $dictionary = $this->getAuthDictionary($version);
  
          if ((is_array($dictionary) && empty($dictionary)) || !isset($dictionary->id)) {
              throw new LocalizedException(__('You must add users in order to enable Basic Authentication.'));
          }
  
          $authItems = $this->dictionaryItemsList($dictionary->id);
  
          if (is_array($authItems) && empty($authItems)) {
              throw new LocalizedException(__('You must add users in order to enable Basic Authentication.'));
          }
      }
docs: Check if authentication dictionary is populated
  
  @param $version
  @throws LocalizedException