how to immediately retrieve the identify after insert

Question

i have a button that inserts a record to an invoice table and InvID is the name of its identity primary key.

  protected void txtSaveInvoice_Click(object sender, EventArgs e)
    {
        SqlConnection conInvoice3 = new SqlConnection
           (@"Data Source=.\SQLEXPRESS;AttachDbFileName=|DataDirectory|\TRANE.mdf;Integrated Security=True;User Instance=True");
        conInvoice3.Open();

        string saveInvoice;
      
        saveInvoice = "INSERT INTO Invoice(EmpID, UnitList, CustomerID, InvoicePrice, Datetime, Comment) Values ('" + UserLabel.Text + "', '" + Label2.Text + "', '" + txtCust.Text + "', '" + Label4.Text + "', '" + LabelDate.Text + "', '" + txtRemark.Text + "') SET @InvID = SCOPE_IDENTITY()";
      
        SqlCommand cmdInvoice = new SqlCommand(saveInvoice, conInvoice3);

        
        cmdInvoice.ExecuteNonQuery();

        Response.Redirect("invoice_redirect.aspx");
        conInvoice3.Close();

    }

googling around i found an article that mentions "scope identity". but the layout of his code is a bit different since im using a very noobish concatenated approach.

my question is how do i integrate a scope identity and display its value on a label?

thanks in advance