oracle functions called from c# code

Try this: 

    DataTable dt = new DataTable();
    
    OracleConnection Conn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
    OracleCommand DbComm = new OracleCommand("SCHEMA.MYFUNCTION", Conn);
    DbComm.CommandType = CommandType.StoredProcedure;
    
    OracleParameter inVar = new OracleParameter("VAR", OracleType.VarChar);
    inVar.Direction = ParameterDirection.Input;
    inVar.Value = "999";
  DbComm.Parameters.Add(inVar);
  DbComm.Parameters.Add("p_cursor", OracleType.Cursor).Direction = ParameterDirection.ReturnValue;

   Conn.Open();
   OracleDataReader reader = DbComm.ExecuteReader();
   dt.Load(reader);
   reader.Close();
   Conn.Close();