Why Testflight showing Ask Permission Request will be sent to Parent/Guardian while purchasing subscription

I am developing an application using in_app_purchase in flutter. it works fine on android but on ios after subscribing to the in-app product(auto-renewing subscription) it asks permission. My client's iPhone does not have family sharing turned on and we are on testflight with internal testing.

I think because of ask permission it is not allowing the purchase completed. the code works perfectly fine in android

my purchase stream code

purchaseUpdates.listen((purchases) async {
      for (PurchaseDetails purchase in purchases) {
        if (purchase.status == PurchaseStatus.error) {
          print(purchase.error.code);
          print(purchase.error.message);
          print(purchase.error.details);
          reUse.show_toast("payment problem if");
          reUse.show_toast(purchase.status.toString());
          in_app_purchase.completePurchase(purchase);
        } else if (purchase.status == PurchaseStatus.purchased) {
          await reUse.add_purchase_details_to_user_account(
            user_id,
            purchase.purchaseID,
            purchase.transactionDate,
            purchase.billingClientPurchase.purchaseToken,
            purchase.billingClientPurchase.signature,
            selected_plan,
            purchase.billingClientPurchase.orderId,
          );
          reUse.show_toast("success");
          in_app_purchase.completePurchase(purchase);
          setState(() {
            subscribed = true;
          });
        } else {
          reUse.show_toast("payment problem else");
          reUse.show_toast(purchase.status.toString());
        }
      }
    });

Edit Gif got cut so here is full video link youtu.be/1umE0EgKLkA

and got it resolved turn sandboxtesting parameter in PurchaseParam class off