ALTER PROCEDURE [dbo].[sp_charge_peni]
@OrderId dbo.DT_ID,
@OutParamStr dbo.DT_PARAMSTR out
AS

CREATE TYPE [dbo].[DT_ID] FROM [int] NOT NULL

using (var sqlConn = new SqlConnection("строка подключения"))
            {
                var sqlCmd = new SqlCommand("sp_charge_peni", sqlConn);
                sqlCmd.CommandType = CommandType.StoredProcedure;
                sqlCmd.Parameters.AddWithValue("@OrderId", Convert.ToInt32(textBox1.Text));
                sqlCmd.Parameters.AddWithValue("@OutParamStr", ""); 

                sqlConn.Open();
                using (SqlDataReader dr = sqlCmd.ExecuteReader())
                {
                    while (dr.Read())
                    {
                        string stringColumn = dr.GetString(dr.GetOrdinal("OutParamStr"));
                    }
                }
            }

Convert.ToInt32(textBox1.Text)

Convert.ToUInt(textBox1.Text)