Auto generate serial number with every Date using C# in Windows Application

I want to save in tblDate

Name: A

Room: 1

Date: 12-06-2021

finally

I have a data like that

Name Room Ticket Date

A      1      001      12-06-2021

B      1      002      12-06-2021

C      1      003      12-06-2021

D      1      001      13-06-2021

E      1      002      14-06-2021

F      1      003      14-06-2021

i want to get ticket 001 to onward daily based on date. how to get solution?

It is not increasing autonumber based on date

here is my code 

private void btnPlay_Click(object sender, EventArgs e)
{
    string today = DateTime.Today.ToString("yyyy-MM-dd");
    int seq = 1;
    string ss = string.Format("IACN-{0}-{1}", today, seq.ToString("D4"));
    lblNo.Text = ss.ToString();
   
     try
    {
        if (string.IsNullOrEmpty(txtDoc.Text) || string.IsNullOrEmpty(txtDoc.Text))
        {
            MessageBox.Show("Missing Data is required! ", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return;
        }
 
        int counter = 0;
        con = new SqlDbConnect();
        con.SqlQuery("select Num from tblDoctorCalls where Num=@Id");
        con.Cmd.Parameters.Add(new SqlParameter("@Id", this.lblNo.Text.Trim()));
        con.RdrEx();
        if (con.Rdr.HasRows)
        {
            while (con.Rdr.Read())
            {
                counter = con.Rdr.GetInt32(0);
                counter += 1;
            };
             
          
        }
        else
        {
            counter = 1;
        }
        con.Rdr.Close();
        //con.SqlQuery("Insert into tblTest(C_Date,D_Name,Desk,Service,P_Name,Ticket,Num) values (@Date,@DName,@Desk,@Service,@PName,@Ticket,@Num)");
        con.SqlQuery("Insert into tblTests(C_Date,D_Name,Desk,Service,P_Name,Num) values (@Date,@DName,@Desk,@Service,@PName,@Num)");
        string paracounter = DateTime.Now.ToString("yyyy-MM-dd") + counter.ToString("D" + 3);
        con.Cmd.Parameters.Add(new SqlParameter("@Date", this.dtpDate.Text));
        con.Cmd.Parameters.Add(new SqlParameter("@DName", this.txtDoc.Text.Trim()));
        con.Cmd.Parameters.Add(new SqlParameter("@Desk", this.txtDe.Text.Trim()));
        con.Cmd.Parameters.Add(new SqlParameter("@Service", this.txtService.Text.Trim()));
        con.Cmd.Parameters.Add(new SqlParameter("@PName", this.txtPatient.Text.Trim()));
        //con.Cmd.Parameters.Add(new SqlParameter("@Ticket", this.txtTicket.Text.Trim()));
        con.Cmd.Parameters.Add(new SqlParameter("@Num", paracounter));
        con.NonQueryEx();
        con.conClose();
        MessageBox.Show("Patient Called...", "Sharaf Hospital", MessageBoxButtons.OK, MessageBoxIcon.Information);
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}