Revenuecat buy downside in Flutter iOS

static Future fetchAndPurchaseLifetimeAccess() async {
    attempt {
      // Fetch choices
      Choices choices = await Purchases.getOfferings();
      Providing? providing = choices.present;
      //Printing choices
      choices.all.forEach(
        (key, worth) {
          print("Choices are ; $key : $worth");
        },
      );
      // Test if lifetime package deal is accessible
      if (providing != null && providing.lifetime != null) {
        debugPrint('Discovered Lifetime Providing');
        // Buy the lifetime package deal
        CustomerInfo purchaserInfo =
            await Purchases.purchasePackage(providing.lifetime!);
        // Test if the entitlement is energetic
        if (purchaserInfo.entitlements.all["zsp2_id"]?.isActive == true) {
          debugPrint("Lifetime entry granted!");

          SharedPreferences prefs = await SharedPreferences.getInstance();
          // Save premium data on SharedPref
          await prefs.setBool('isPremium', true);
          return true;
        }
      } else {
        debugPrint("Lifetime package deal not out there.");
      }
    } catch (e) {
      debugPrint("Error buying: $e");
    }
    return false;
  }

flutter: Attempting to buy
flutter: Error buying: PlatformException(23, There is a matter along with your configuration. Test the underlying error for extra particulars. There's an issue along with your configuration. Not one of the merchandise registered within the RevenueCat dashboard might be fetched from App Retailer Join (or the StoreKit Configuration file if one is getting used).
flutter: Extra info: https://rev.cat/why-are-offerings-empty, {readable_error_code: CONFIGURATION_ERROR, underlyingErrorMessage: , message: There is a matter along with your configuration. Test the underlying error for extra particulars. There's an issue along with your configuration. Not one of the merchandise registered within the RevenueCat dashboard might be fetched from App Retailer Join (or the StoreKit Configuration file if one is getting used).
flutter: Extra info: https://rev.cat/why-are-offerings-empty, code: 23, readableErrorCode: CONFIGURATION_ERROR}, null)

What’s fallacious right here?
Revenuecat iOS setup in documentation is little bit complicated.