not able to fetch data by ID in flutter using Getx

i’m trying to fetch a list of sub categories based on category id, for example:

• Category A has 3 sub categories: A1 – A2 – A3

My backend works fine, I pass the category_id to the function and it returns me a list of sub categories having the category_id.
Since i’m new to getx, I tried passing the category_id as a route parameter but i’m not able to show the list of sub categories. In fact I didn’t get how to pass the category_id while in the UI.

Here is my repo:

Future<Response> getSubCategoriesListByCategory(int categ_id) async {
    return await apiClient.getData('shop/category/$categ_id');
  }

Here is my controller:

List<dynamic> _subCategoriesListByCategory = [];
List<dynamic> get subCategoriesListByCategory => _subCategoriesListByCategory;

  bool _isLoaded = false;
  bool get isLoaded => _isLoaded;

  Future<void> getSubCategoriesByCategoryId(int cat_id) async {
    Response response =
        await subCategoriesRepo.getSubCategoriesListByCategory(cat_id);
    if (response.statusCode == 200) {
      _subCategoriesListByCategory = [];
      _subCategoriesListByCategory.addAll(response.body);
      _isLoaded = true;
      //print(categoriesList);
      update(); // = setState();
    } else {}
  }

Here is my RouteHelper:

GetPage(
        name: subCategory,
        page: () {
          var catId = Get.parameters['catId'];
          return SubCategoriesPage(catId: int.parse(catId!));
        },
        transition: Transition.fadeIn),

And here is my UI:

GetBuilder<SubCategoriesController>(builder: (subCategories) {
              return GridView.count(
                crossAxisCount: 2,
                shrinkWrap: true,
                physics: ScrollPhysics(),
                mainAxisSpacing: 16,
                crossAxisSpacing: 16,
                childAspectRatio: 90 / 100,
                padding: EdgeInsets.all(16),
                children: List.generate(
                    subCategories.subCategoriesListByCategory.length, (index) {
                  return _buildSingleSubCategory(
                      index,
                      SubCategoryModel.fromJson(
                          subCategories.subCategoriesListByCategory[index]));
                }),
              );
            })

Code from home page where i’m passing the category_id:

onTap: () {
          Get.toNamed(RouteHelper.getSubCategory(category.id));
        },

• I’m able to print the clicked category’s id in the subs page which means it’s passed correctly, also i’m getting GOING TO ROUTE /sub-category?catId=3

Noting that i’m priting the specific category_id correctly in the sub categories page, I couldn’t fetch the specific data related to them. Any suggestion on how to solve this?