WebApi add class name in json response

I've been looking all over the place for a way to add the name of the class to the json response from my API. This my first attempt at creating an API, so please any help would be appreciated.

From my Data layer

public static List<Invoices> GetAllInvoices()
        {
            List<Invoices> inslist = new List<Invoices>();
            using (SqlConnection con = new SqlConnection(Connection.sql))
            {
                SqlCommand cmd = new SqlCommand("_Sp_GetOperationsInvoices", con);
                cmd.CommandType = CommandType.StoredProcedure;

                try
                {
                    con.Open();
                    cmd.ExecuteNonQuery();

                    using (SqlDataReader dr = cmd.ExecuteReader())
                    {
                        while (dr.Read())
                        {
                            inslist.Add(new Invoices()
                            {
                                ID = Convert.ToInt32(dr["ID"]),
                                BillToName = dr["BillToName"].ToString(),
                                ClientName = dr["ClientName"].ToString(),
                                ClientCode = dr["ClientCode"].ToString(),
                                InvoiceNumber = dr["InvoiceNumber"].ToString(),
                                InvoiceDate = DateTime.Parse(dr["InvoiceDate"].ToString()),
                                InvoiceDueDate = DateTime.Parse(dr["InvoiceDueDate"].ToString()),
                                AmountDue = dr["AmountDue"].ToString(),
                                OFFC = dr["OFFC"].ToString(),
                                DateImported = DateTime.Parse(dr["DateImported"].ToString()),
                                DaysFromDueDate = int.Parse(dr["DaysFromDueDate"].ToString()),
                            });
                        }
                    }
                    return inslist;
                }
                catch (Exception ex)
                {
                    return inslist;
                }
            }
        }

From my Controller

[HttpGet]
        [Route("api/GetAllInvoices")]
        public List<Invoices> GetAll()
        {           
            var Data = Data_Layer.GetAllInvoices();
            return Data;
        }

The models

public class Records
    {
        public List<Invoices> invoices { get; set; }
    }
    public class Invoices
    {
        public int ID { get; set; }

        public string BillToName { get; set; }

        public string ClientName { get; set; }

        public string ClientCode { get; set; }

        public string InvoiceNumber { get; set; }

        public DateTime? InvoiceDate { get; set; }

        public DateTime? InvoiceDueDate { get; set; }

        public string AmountDue { get; set; }

        public string OFFC { get; set; }

        public DateTime? DateImported { get; set; }

        public int? DaysFromDueDate { get; set; }
    }

Right now the response looks like the following:

[
{
"ID": 1,
"BillToName": "Kurian",
"ClientName": "Fort Myers",
"ClientCode": " C00687",
"InvoiceNumber": "INV2484899",
"InvoiceDate": "2023-05-18T00:00:00",
"InvoiceDueDate": "2023-06-17T00:00:00",
"AmountDue": " $110.00",
"OFFC": "FTM",
"DateImported": "2023-05-18T00:00:00",
"DaysFromDueDate": 30
},
{
"ID": 2,
"BillToName": "Levine",
"ClientName": "Fort Lauderdale",
"ClientCode": " C00686",
"InvoiceNumber": "INV2445218",
"InvoiceDate": "2023-04-04T00:00:00",
"InvoiceDueDate": "2023-05-04T00:00:00",
"AmountDue": " $570.00",
"OFFC": "FTL",
"DateImported": "2023-05-19T00:00:00",
"DaysFromDueDate": 30
}
]

I would like it to be

[
Data:{
"ID": 1,
"BillToName": "Kurian",
"ClientName": "Fort Myers",
"ClientCode": " C00687",
"InvoiceNumber": "INV2484899",
"InvoiceDate": "2023-05-18T00:00:00",
"InvoiceDueDate": "2023-06-17T00:00:00",
"AmountDue": " $110.00",
"OFFC": "FTM",
"DateImported": "2023-05-18T00:00:00",
"DaysFromDueDate": 30
},
{
"ID": 2,
"BillToName": "Levine",
"ClientName": "Fort Lauderdale",
"ClientCode": " C00686",
"InvoiceNumber": "INV2445218",
"InvoiceDate": "2023-04-04T00:00:00",
"InvoiceDueDate": "2023-05-04T00:00:00",
"AmountDue": " $570.00",
"OFFC": "FTL",
"DateImported": "2023-05-19T00:00:00",
"DaysFromDueDate": 30
}
]

The simplest workaround would be to just simply use a dictionary.
For example:

public IDictionary<string, T> Helper<T>(T obj)
{
	return new Dictionary<string, T>() { { obj?.GetType().Name ?? "null", obj } };
}

usage example:

public dynamic Get()
{
	return Helper(new Test());
}

Output:

{
  "Test": {
    "id": 1,
    "name": "test",
    "x": 1.11
  }
}

You must Change Output Action To IActionResult and Create A Model For Create Prefix "Data"

 public IActionResult GetAll()
    {
        var Data = Data_Layer.GetAllInvoices();

        var model = new
        {
            Data = Data
        };
        return Ok(model);
    }