Recently i was working on intergrating my json value to the flutter design and i came across an error of

type ‘_Map<String, Object>’ is not a subtype of type ‘int’ in type cast

and i don’t know why am i having this error, can somebody explain this and give me ideas to rectify it ,thank you.

codes:

GestureDetector(
                  onTap: () {
                    Navigator.pushNamed(
                      context,
                      confirmation,
                      arguments: {
                        'itemCount': _itemCount,
                        'product': widget.product,
                      },
                    );
                  },

_itemcount is an integer value and widget.product is a list value of a data model

final int itemCount;
  final Product product;
  const Previewpage({super.key, required this.itemCount, required this.product});

this is page code that i want to get value for that code of navigator

case preview: // Use the constant from constants.dart
        final count = settings.arguments as int;
        final product = settings.arguments as Product;
        return MaterialPageRoute(
          builder: (context) => Previewpage(
            itemCount: count,
            product: product,
          ),
        );

This is route generator code that also pass arguments.

can somebody help me with this and also explain me why we use a route generator for routing.
I think it off like a gate keeper to another widget when wanted to pass values sort of double confirmation.That’s all