type '(dynamic) => Product' is not a subtype of type '(String, dynamic) => MapEntry<dynamic, dynamic>' of 'transform' - flutter

Question

I am trying to consume data from an API. I used quicktype.io to create a model class to parse the JSON data. The JSON data contains nested maps.
Now I am getting an error
The error is [type '(dynamic) => Product' is not a subtype of type '(String, dynamic) => MapEntry<dynamic, dynamic>' of 'transform']
This is the code for API request;
Future<void> setSpecials(String restaurantId) async {
try {
final url = Uri.parse(
ENDPOINT + 'restaurant/specials?restaurantId=$restaurantId&page=0');
final response = await http.get(url);
print(response.statusCode);
if (response.statusCode == 200) {
final List<Product> specials = productFromJson(response.body);
_specialsList = specials;
}
print(_specialsList.length);
notifyListeners();
} catch (e) {
print(e.toString());
}}
This is the model
List<Product> productFromJson(String str) => List<Product>.from(json.decode(str).map((x) => Product.fromJson(x)));
String productToJson(List<Product> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Product {
Product({
required this.id,
required this.name,
required this.image,
required this.description,
required this.isFavourite,
required this.dishes,
required this.diet,
});
String id;
String name;
String image;
String description;
bool isFavourite;
List<Dish> dishes;
String diet;
factory Product.fromJson(Map<String, dynamic> json) => Product(
id: json["_id"],
name: json["name"],
image: json["image"],
description: json["description"],
isFavourite: json["isFavourite"],
dishes: List<Dish>.from(json["dishes"].map((x) => Dish.fromJson(x))),
diet: json["diet"] == null ? null : json["diet"],
);
Map<String, dynamic> toJson() => {
"_id": id,
"name": name,
"image": image,
"description": description,
"isFavourite": isFavourite,
"dishes": List<dynamic>.from(dishes.map((x) => x.toJson())),
"diet": diet == null ? null : diet,
};
}
class Dish {
Dish({
required this.name,
required this.price,
required this.offerIds,
required this.id,
});
String name;
double price;
List<dynamic> offerIds;
String id;
factory Dish.fromJson(Map<String, dynamic> json) => Dish(
name: json["name"],
price: double.parse(json["price"].toString()),
offerIds: List<dynamic>.from(json["offerIds"].map((x) => x)),
id: json["_id"],
);
Map<String, dynamic> toJson() => {
"name": name,
"price": price,
"offerIds": List<dynamic>.from(offerIds.map((x) => x)),
"_id": id,
};
}
The JSON data is
[
{
"_id": "60edb147d91f7820c80585c9",
"name": "Chicken Biriyani",
"image": "localhost:3031\\images\\1626190484369-chicken-Biryani.jpg",
"description": "Chicken, Motton",
"isFavourite": false,
"dishes": [
{
"name": "Full",
"price": 200,
"offerIds": [],
"_id": "610e1cd618319924b45ef9cd"
},
{
"name": "Half",
"price": 150,
"offerIds": [],
"_id": "610e1cd618319924b45ef9ce"
},
{
"name": "Quarter",
"price": 100,
"offerIds": [],
"_id": "610e1cd618319924b45ef9cf"
}
]
},
{
"_id": "610cb83c231052429899df76",
"name": "Shavrma",
"image": "157.245.96.189:3031/images/1632371901688-IMG-20210922-WA0123.jpg",
"description": "Chicken Shavrma",
"diet": "Veg",
"isFavourite": false,
"dishes": [
{
"name": "Plate",
"price": 80,
"offerIds": [],
"_id": "610cb83c231052429899df77"
},
{
"name": "Roll",
"price": 60,
"offerIds": [],
"_id": "610cb83c231052429899df78"
}
]
}
]