I need to upload and update file bytes from C# to SQL Server, but I am getting this error in C#:

Microsoft.Data.SqlClient.SqlException: ‘Implicit conversion from data type nvarchar(max) to varbinary(max) is not allowed. Use the CONVERT function to run this query.’

C# code:

public async Task<dynamic> UpdateBulkData(IList<EodUpdateDto> eods)
{
    string strTrace = MethodLogger.GetExecutionInfo(MethodBase.GetCurrentMethod());
    logger.LogDebug($"Executing {strTrace} with parameter : {JsonSerializer.Serialize(eods)}");
 
    string sqlQuery = $"{StoredProcedures.UPDATE_BULK_EOD} @EODS";
    var paramEods = new SqlParameter() { ParameterName = "@EODS", Value = eods.ToDataTable(), SqlDbType = SqlDbType.Structured, TypeName = "EODType" };
    await sqlExecutor.ExecuteSqlRawAsync(sqlQuery, [paramEods]);

    return true;
}

Code Definition of ToDataTable

public static DataTable ToDataTable<T>(this IList<T> items)
{
     DataTable dataTable = new(typeof(T).Name);
 
     //Get all the properties
     PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
     foreach (PropertyInfo prop in Props)
     {
         //Defining type of data column gives proper data table 
         dynamic? type = (prop.PropertyType.IsGenericType && prop.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>) ? Nullable.GetUnderlyingType(prop.PropertyType) : prop.PropertyType);
         //Setting column names as Property names
         dataTable.Columns.Add(prop.Name, type);
     }
     if (items != null && items.Count > 0)
     {
         foreach (T item in items)
         {
             dynamic values = new object[Props.Length];
             for (int i = 0; i < Props.Length; i++)
             {
                 //inserting property values to datatable rows
                 values[i] = Props[i].GetValue(item, null);
             }
             dataTable.Rows.Add(values);
         }
     }
     //put a breakpoint here and check datatable
     return dataTable;
}

Here value of StoredProcedures.UPDATE_BULK_EOD is usp_UpdateEODData_U.

This is the definition of EodUpdateDto model class:

public class EodUpdateDto
{
    public int Id { get; set; }
    public string ActionBy { get; set; } = default!;
    public bool Accepted { get; set; }
    public bool VerifySelfPay { get; set; }
    public string Claim { get; set; } = default!;
    public bool OnHold { get; set; }
    public string HoldReason { get; set; } = default!;
    public string AttachFileName { get; set; } = default!;
    public string AttachFileType { get; set; } = default!;
    public byte[]? AttachFileContent { get; set; } = default!;
}

Here is the design of the SQL Server user-defined table type:

CREATE TYPE [dbo].[EODType] AS TABLE
(
    [ID] [int] NULL,
    [ActionBy] [varchar](200) NOT NULL,
    [Accepted] [bit] NULL,
    [VerifySelfPay] [bit] NULL,
    [Claim] [varchar](50) NULL,
    [OnHold] [bit] NULL,
    [HoldReason] [varchar](200) NULL,
    [AttachFileName] [varchar](300) NULL,
    [AttachFileContent] [varbinary](max) NULL,
    [AttachFileType] [varchar](50) NULL
)

This is the stored procedure to which the data is passed:

ALTER PROCEDURE [dbo].[usp_UpdateEODData_U]
    @EODS [dbo].[EODType] READONLY
AS
BEGIN
    SET NOCOUNT ON;
 
    UPDATE EOD 
    SET 
        Accepted = E2.Accepted, 
        VerifySelfPay = E2.VerifySelfPay, 
        Claim = E2.Claim, 
        OnHold = E2.OnHold, 
        HoldReason = E2.HoldReason,
        HoldDate = IIF(E2.HoldReason IS NOT NULL, dbo.GetDateEST(), null),
        AttachFileName = E2.AttachFileName,
        AttachFileContent = E2.AttachFileContent,
        AttachFileType = E2.AttachFileType,
        ActionBy = E2.ActionBy
    FROM EOD E1
    INNER JOIN @EODS E2 ON E1.ID = E2.ID;
END