Cannot get countrycode in ios

[congfandi]

  Future<void>_tryGetCountryCode()async {
    try {
      final countryCode = await FlutterSimCountryCode.simCountryCode;
      if (countryCode == null) {
        return;
      }
      print("selected phone code $countryCode ");
      // currentCountryCode = countryCode;
    } catch (e) {
      return;
    }
  }

this code always retur -- in ios, but workinug well in android