code: protected function trans(string $key, string $member, array $replace = [], ?string $locale = null)
      {
          return $this->translator->trans(
              "jsonapi::errors.{$key}.{$member}",
              $replace,
              $locale
          ) ?: null;
      }
docs: Translate an error member value.
  
  @param string $key
  the key for the JSON API error object.
  @param string $member
  the JSON API error object member name.
  @param array $replace
  @param string|null $locale
  @return string|null