GOJS OrgChartDiagram

How can I add elements new elements in nodeDataArray object. When I am trying to add new element it doesnt show up.
{ “class”: “go.TreeModel”,
“nodeDataArray”: [
{“key”:“1”, “name”:“Stella Payne Diaz”, “title”:“CEO”, “sysID”: “gf12245”},

For example, in above array I have added sysID but it is not showing up in the diagram.
Also let me know how can i retrieve these elements

What do you mean by “elements”?

If you want to add a node to the model, you can either do so by adding an object to the “nodeDataArray”, or you can call Model.addNodeData.

If you want to add textual information that is shown in the node, you need to add the properties to the data, as you already have, and you need to augment the node template to include TextBlocks and other GraphObject elements so that the node looks the way that you would like.

I recommend reading Get Started with GoJS and then at least the first dozen pages of the Introduction, GoJS Introduction -- Northwoods Software.

And read the node templates in the samples carefully.