code: public function setNotifyType($notifyType)
      {
          if (!\in_array($notifyType, [self::NOTIFY_EMAIL, self::NOTIFY_PHONE], true)) {
              throw new RuntimeException(Tools::poorManTranslate('fts-shared', 'Invalid notify type.'));
          }
  
          return $this->add('NT', $notifyType);
      }
docs: Set notify type (bank-specific)
  
  @param string $notifyType Notify type - see constants NOTIFY_*
  @return QRPayment
  @throws RuntimeException