I am creating a wishlist true false functionality. In _favListData List variable I have data but in this variable my data is different

This is my _favListData List data, in this data i have two object but different type.

[
  {
    uuid: beadecf3-7f43-4086-8645-669f418d60e2,
    customerId: 18d74dc1-4254-4b0b-a434-32504b6d42b3,
    productId: 12944,
    name: HealthTablets,
    regular_price: 10,
    sale_price: 9,
    category: [
      {
        id: 16,
        name: AllProducts,
        slug: allproducts
      },
      {
        id: 57,
        name: Behavioral,
        slug: behavioral
      }
    ],
    image: [
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12936,
        date_created: 2022-08-19T09: 41: 19,
        date_created_gmt: 2022-08-19T09: 41: 19,
        date_modified: 2022-08-19T09: 41: 19,
        date_modified_gmt: 2022-08-19T09: 41: 19,
        src: https: //mycwc.org/wp-content/uploads/2022/08/4.jpg,
        name: 4,
        alt: 
      },
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12933,
        date_created: 2022-08-19T09: 39: 37,
        date_created_gmt: 2022-08-19T09: 39: 37,
        date_modified: 2022-08-19T09: 39: 37,
        date_modified_gmt: 2022-08-19T09: 39: 37,
        src: https: //mycwc.org/wp-content/uploads/2022/08/6.jpg,
        name: 6,
        alt: 
      }
    ]
  },
  {
    quantity: 1,
    inWishlist: true,
    _id: 6318b77818f512454aa5bc84,
    productId: 12942,
    categoryId: 16,
    uuid: a2b6736b-1f9c-4a2a-84d2-4271ca69e2b5,
    customerId: 18d74dc1-4254-4b0b-a434-32504b6d42b3,
    createdAt: 2022-09-07T15: 23: 36.121Z,
    updatedAt: 2022-09-07T15: 23: 36.121Z,
    __v: 0
  }
]

so from _favListData List variable I want to check productId and from another list variable Id is matching or not . I am using this functionalty.

  int isExistFav(dynamic data) {

    final isExist=
    _favListData.indexWhere((element) =>  element["productId"] == data["id"]);

    return isExist;
  }

Note: when in _favListData List i have same type of object then is working fine. like this--> Here these data is different id but type is same(key)

[
  {
    uuid: beadecf3-7f43-4086-8645-669f418d60e2,
    customerId: 18d74dc1-4254-4b0b-a434-32504b6d42b3,
    productId: 12944,
    name: HealthTablets,
    regular_price: 10,
    sale_price: 9,
    category: [
      {
        id: 16,
        name: AllProducts,
        slug: allproducts
      },
      {
        id: 57,
        name: Behavioral,
        slug: behavioral
      }
    ],
    image: [
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12936,
        date_created: 2022-08-19T09: 41: 19,
        date_created_gmt: 2022-08-19T09: 41: 19,
        date_modified: 2022-08-19T09: 41: 19,
        date_modified_gmt: 2022-08-19T09: 41: 19,
        src: https: //mycwc.org/wp-content/uploads/2022/08/4.jpg,
        name: 4,
        alt: 
      },
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12933,
        date_created: 2022-08-19T09: 39: 37,
        date_created_gmt: 2022-08-19T09: 39: 37,
        date_modified: 2022-08-19T09: 39: 37,
        date_modified_gmt: 2022-08-19T09: 39: 37,
        src: https: //mycwc.org/wp-content/uploads/2022/08/6.jpg,
        name: 6,
        alt: 
      }
    ]
  },

{
    "uuid": "e923567d-272c-421b-85c4-c29d9e23cc7c",
    "customerId": "18d74dc1-4254-4b0b-a434-32504b6d42b3",
    "productId": 12944,
    name: Cancer,
    regular_price: 10,
    sale_price: 9,
    category: [
      {
        id: 16,
        name: AllProducts,
        slug: allproducts
      },
      {
        id: 57,
        name: Behavioral,
        slug: behavioral
      }
    ],
    image: [
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12936,
        date_created: 2022-08-19T09: 41: 19,
        date_created_gmt: 2022-08-19T09: 41: 19,
        date_modified: 2022-08-19T09: 41: 19,
        date_modified_gmt: 2022-08-19T09: 41: 19,
        src: https: //mycwc.org/wp-content/uploads/2022/08/4.jpg,
        name: 4,
        alt: 
      },
      {
        id: 12934,
        date_created: 2022-08-19T09: 40: 30,
        date_created_gmt: 2022-08-19T09: 40: 30,
        date_modified: 2022-08-19T09: 40: 30,
        date_modified_gmt: 2022-08-19T09: 40: 30,
        src: https: //mycwc.org/wp-content/uploads/2022/08/10.jpg,
        name: 10,
        alt: 
      },
      {
        id: 12933,
        date_created: 2022-08-19T09: 39: 37,
        date_created_gmt: 2022-08-19T09: 39: 37,
        date_modified: 2022-08-19T09: 39: 37,
        date_modified_gmt: 2022-08-19T09: 39: 37,
        src: https: //mycwc.org/wp-content/uploads/2022/08/6.jpg,
        name: 6,
        alt: 
      }
    ]
  },
]