type '_Map<String, List<Map<String, Map<String, String>>>>' is not a subtype of type 'String' in flutter

[{
    "getOtherCategoryCompaniesList_resp": [{
            "messageInfo": {
                "message_text": "Other Services List.",
                "alert_title": "Services List",
                "product_category_id": "56",
                "Success": "1"
            }
        },
        {
            "companies": [{
                    "product_type_id": 1946,
                    "company_id": 609,
                    "product_name": "_All Puja",
                    "product_company_logo": "https://bhagva.in/imgs/icons/prod_category/logo.png"
                },
                {
                    "product_type_id": 1753,
                    "company_id": 535,
                    "product_name": "Aasa Maai Vrat Katha",
                    "product_company_logo": "https://bhagva.in/imgs/icons/prod_category/logo.png"
                }
            ]
        }
    ]
}]

This is my model class which i have generate online from json to pojo in dart

class Poojlistmodel {
  int? producttypeid;
  int? companyid;
  String? productname;
  String? productcompanylogo;

  Poojlistmodel(
      {this.producttypeid,
      this.companyid,
      this.productname,
      this.productcompanylogo});

  Poojlistmodel.fromJson(Map<String, dynamic> json) {
    producttypeid = json['product_type_id'];
    companyid = json['company_id'];
    productname = json['product_name'];
    productcompanylogo = json['product_company_logo'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = Map<String, dynamic>();
    data['product_type_id'] = producttypeid;
    data['company_id'] = companyid;
    data['product_name'] = productname;
    data['product_company_logo'] = productcompanylogo;
    return data;
  }
}

class GetOtherCategoryCompaniesListResp {
  MessageInfo? messageInfo;
  List<Poojlistmodel?>? companies;

  GetOtherCategoryCompaniesListResp({this.messageInfo, this.companies});

  GetOtherCategoryCompaniesListResp.fromJson(Map<String, dynamic> json) {
    messageInfo = json['messageInfo'] != null
        ? MessageInfo?.fromJson(json['messageInfo'])
        : null;
    if (json['companies'] != null) {
      companies = <Poojlistmodel>[];
      json['companies'].forEach((v) {
        companies!.add(Poojlistmodel.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = Map<String, dynamic>();
    data['messageInfo'] = messageInfo!.toJson();
    data['companies'] =
        companies != null ? companies!.map((v) => v?.toJson()).toList() : null;
    return data;
  }
}

class MessageInfo {
  String? messagetext;
  String? alerttitle;
  String? productcategoryid;
  String? success;

  MessageInfo(
      {this.messagetext,
      this.alerttitle,
      this.productcategoryid,
      this.success});

  MessageInfo.fromJson(Map<String, dynamic> json) {
    messagetext = json['message_text'];
    alerttitle = json['alert_title'];
    productcategoryid = json['product_category_id'];
    success = json['Success'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = Map<String, dynamic>();
    data['message_text'] = messagetext;
    data['alert_title'] = alerttitle;
    data['product_category_id'] = productcategoryid;
    data['Success'] = success;
    return data;
  }
}

class Root {
  List<GetOtherCategoryCompaniesListResp?>? getOtherCategoryCompaniesListresp;

  Root({this.getOtherCategoryCompaniesListresp});

  Root.fromJson(Map<String, dynamic> json) {
    if (json['getOtherCategoryCompaniesList_resp'] != null) {
      getOtherCategoryCompaniesListresp = <GetOtherCategoryCompaniesListResp>[];
      json['getOtherCategoryCompaniesList_resp'].forEach((v) {
        getOtherCategoryCompaniesListresp!
            .add(GetOtherCategoryCompaniesListResp.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = Map<String, dynamic>();
    data['getOtherCategoryCompaniesList_resp'] =
        getOtherCategoryCompaniesListresp != null
            ? getOtherCategoryCompaniesListresp!
                .map((v) => v?.toJson())
                .toList()
            : null;
    return data;
  }
}

This code i am using to network hit

class MySpecilistRepo {
  final BaseApiServices _apiServices = NetworkApiService();

  Future<dynamic> dashboardApi(String userId,String productCategoryId) async {
    try {
      var params = {
        "getOtherCategoryCompaniesList_req": [
          {
            "requestInfo": {
              "user_id": userId,
              "product_category_id": productCategoryId
            }
          }
        ]
      };

      dynamic response =
          await _apiServices.authApiResponse(AppUrl.GET_LIST_OF_POOJA, params);
      print("dashboard $response");
      return Poojlistmodel.fromJson(response);
    } catch (e) {
      rethrow;
    }
  }
}

When i run code i am getting exception that type ‘_Map<String, List<Map<String, Map<String, String>>>>’ is not a subtype of type ‘String’ i don’t know where i am doing mistake while i have generate model class using online please help me where i am doing wrong i trying first time network hit in flutter .

Thanks