I'm looking to create an Email Send Definition via WSProxy. I am trying to mirror the SOAP Envelope for my proxy script.

I am getting an error when trying to create it; Error Code: 2...

<script runat='server'>
Platform.Load("core", "1.1.1");

//Get External/CustomerKey of ObjectID based on DE Name
function getDEobjectID(deName){
var prox = new Script.Util.WSProxy();
var cols = ["ObjectID"];
var filter = {
    Property: "Name",
    SimpleOperator: "equals",
    Value: deName
};  
  
var result = prox.retrieve("DataExtension", cols, filter);
var objectID = result.Results[0].ObjectID;  

Write("ObjectID: " + objectID + "<br><br>");

return objectID;
};


var deName = "DEName";
var objectID = getDEobjectID(deName);


var prox = new Script.Util.WSProxy();
  
var esd = {
    "Name": "SOAP_ESD_test1",
    "SendDefinitionList": [{
        "CustomObjectID": objectID,
        "DataSourceTypeID": "CustomObject"
    }],
    "Email": {
        "ID": 6499
    },
    "SendClassification": {
        "CustomerKey": "Default Commercial"
    }
};


try {

    var res = prox.createItem("EmailSendDefinition", esd);
    Write('Response: ' + Stringify(res) + '<br><br>');

} catch (e) {
    Write(Stringify(e));
}

</script>