"Conversion failed when converting the varchar value '@IDPRO' to data type int."

 class DataAccessLayer
    {
        SqlConnection SQLcn;

        //This Constructor Inisialize The Connection Object
       
        public DataAccessLyer()
        {

     SQLcn = new SqlConnection(@"server=.\SQLEXPRESS;database=Product_DB;integrated security=true");
            //

        }

        //Method to open connection
        public void open()
        {
            if (SQLcn.State != ConnectionState.Open)
            {
                SQLcn.Open();
            }
        }

        //Method to close connection
        public void close()
        {
            if (SQLcn.State == ConnectionState.Open)
            {
                SQLcn.Close();
            }
        }


        //METHOD TO READ DATA
        public DataTable selectdata(string storage_proc, SqlParameter[] param)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = storage_proc;
            cmd.Connection = SQLcn;

            if (param != null)
            {

                for (int i = 0; i < param.Length; i++)
                {

                    cmd.Parameters.Add(param[i]);
                }
            }

            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);
            return dt;
        
        
        }


        //METHOD TO INSERT ,UPDATE ,DELATE
        public void Executecommand(string storage_proc, SqlParameter[] param)
          {

            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = storage_proc;
            cmd.Connection = SQLcn;
            if (param != null)
            {

                cmd.Parameters.AddRange(param);
            }

            cmd.ExecuteNonQuery();

          } 


class CLS_PRODUCT
    {
        public DataTable GETCATOGRY()
        {
            DAL.DataAccessLyer DAL = new DAL.DataAccessLyer();
            DAL.open();
            DataTable dt = new DataTable();
            dt = DAL.selectdata("GETCATOGRY", null);
            DAL.close();
            return dt;
        }

        public void ADD_PRODUCT(string ID_PRODUCT, string LABEL, int QTE, string PRICE, byte[]IMAGE, int ID_CAT)
        {
            DAL.DataAccessLyer DAL = new DAL.DataAccessLyer();
            DAL.open();
            SqlParameter [] param=new SqlParameter[6];

            param[0] = new SqlParameter("@IDPRO", SqlDbType.VarChar, 50);
            param[0].Value = ID_PRODUCT;

            param[1] = new SqlParameter("@LABELPRO", SqlDbType.VarChar, 50);
            param[1].Value = LABEL;

            param[2] = new SqlParameter("@QTEPRO", SqlDbType.Int);
            param[2].Value = QTE;

            param[3] = new SqlParameter("@PRICEPRO", SqlDbType.VarChar, 50);
            param[3].Value = PRICE;

            param[4] = new SqlParameter("@IMAGEPRO", SqlDbType.Image);
            param[4].Value = IMAGE;

            param[5] = new SqlParameter("@IDCAT", SqlDbType.Int);
            param[5].Value = ID_CAT;

            DAL.Executecommand("ADD_PRODUCT",param);
            DAL.close();
                

           }

ALTER PROC [dbo].[ADD_PRODUCT]

  @IDPRO varchar(50)  ,
  @LABELPRO varchar(50),
  @QTEPRO int,
  @PRICEPRO varchar(50),
  @IMAGEPRO image,
  @IDCAT int
 <small><big></big></small>
 AS

INSERT INTO PRODUCTS
           (ID_PRODUCT
           ,LABEL_PRODUCT
           ,QTE_PRODUCT
           ,PRICE_PRODUCT
           ,IMAGE_PRODUCT
           ,ID_CAT)
     VALUES
       (@IDPRO 
          , @LABELPRO 
          , @QTEPRO
          , @PRICEPRO 
          , @IMAGEPRO
          , @IDCAT)

ALTER PROC [dbo].[GETCATOGRY]
AS
SELECT * FROM CATEGORY

using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;


namespace PRODUCTS_MANAGMENT.PL
{
    public partial class Frm_Add_prodc : Form
    {
        public string STATE = "ADD";
    BL.CLS_PRODUCT PRC = new BL.CLS_PRODUCT();
        public Frm_Add_prodc()
        {
            InitializeComponent();
            cmbCAT.DataSource = PRC.GETCATOGRY();
            cmbCAT.DisplayMember = "DESCREPTION_CAT";
            cmbCAT.ValueMember = "ID_CAT";
        }
 private void btnADD_Click(object sender, EventArgs e)
        {
            
                MemoryStream ms = new MemoryStream();
                picprodc.Image.Save(ms, picprodc.Image.RawFormat);
                byte[] IMAGE = ms.ToArray();

                PRC.ADD_PRODUCT(TXTREF.Text, TXTDES.Text,   Convert.ToInt32(txtqnt.Text), txtprice.Text, IMAGE, Convert.ToInt32(cmbCAT.SelectedValue));
                MessageBox.Show("SUCCESS ADDING", "ADD OPERATION ", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }