How can I update my List<Map<String,dynamic>> using GetX in flutter

Question

How can I update my List<Map<String,dynamic>> in flutter, I have tried using it like this controller.reportData.value[index]['customer'] and controller.reportData[index].value['customer]

Following is my code: Controller Class:

  RxList<Map<String, dynamic>> reportData = <Map<String, dynamic>>[].obs;

  Future<void> getReport() async {
    await BaseClient.safeApiCall(
      ApiConstants.CUSTOMER_ITEM_SUMMARY,
      RequestType.post,
      headers: await BaseClient.generateHeaders(),
      data: {
        'fromDate': fromDatePickerController.text,
        'toDate': toDatePickerController.text
      },
      onSuccess: (json) {
        reportData.clear();
        json.data.forEach((data) {
          reportData.add({
            'customer': '${data['customerCompanyName']}',
            'qty': '${data['quantity']}',
            'amount': '\$${data['subTotal']}',
            'cogs': '\$${data['cogs']}',
            'net': '\$$net',
            'gain': '$gain%',
          });
        });
      },
      onError: (e) {},
    );
  }

View Class:

ListView.builder(
  physics: const NeverScrollableScrollPhysics(),
  itemCount: controller.reportData.length,
  shrinkWrap: true,
  padding: const EdgeInsets.symmetric(
    vertical: 10,
  ),
  itemBuilder: (context, index) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 20),
      child: ListTile(
        title: Row(
          children: [
            Expanded(
              flex: 5,
              child: Text(
                controller.reportData.value[index]['customer'],
                textAlign: TextAlign.left,
                overflow: TextOverflow.ellipsis,
                style: context.bodyLarge.copyWith(
                  fontWeight: FontWeight.normal,
                ),
              ),
            ),
            ...    
          ],
        ),
      ),
    );
  },
),

I have tried doing update(); and it doesn't work.