Custom column serilog with sink.MySQL

how can i custom column in Sink.MySQL with appsetting.json configuration?

i try to use

"columnOptionsSection": {
                    "customColumns": [
                      {
                        "ColumnName": "UserId",
                        "DataType": "nvarchar",
                        "DataLength": 450,
                        "AllowNull": true
                      },
                      {
                        "ColumnName": "UserName",
                        "DataType": "nvarchar",
                        "DataLength": 256,
                        "AllowNull": true

                      }
                    ]


                  }

but don't work.