code: public static function getConfigDefinitions()
      {
          $definitions = parent::getConfigDefinitions();
  
          return $definitions + [
              'apiVersion' => [
                  'valid' => ['string'],
                  'default' => \DTS\eBaySDK\FileTransfer\Services\FileTransferService::API_VERSION
              ],
              'authToken' => [
                  'valid' => ['string'],
                  'required' => true
              ]
          ];
      }
docs: Returns definitions for each configuration option that is supported.
  
  @return array An associative array of configuration definitions.