Assign to specific points of the visible part

I try to assign it to the places I marked, but it doesn’t

I’m trying this

diagram.viewportBounds.left + " " + diagram.viewportBounds.top

    var location;
                    if (args.parameters.ModelInformationLocation == 0) {
                        location = diagram.viewportBounds.left + " " + diagram.viewportBounds.top;
                    } else if (args.parameters.ModelInformationLocation == 1) {
                        location = diagram.viewportBounds.right + " " + diagram.viewportBounds.top;
                    } else if (args.parameters.ModelInformationLocation == 2) {
                        location = diagram.viewportBounds.left + " " + diagram.viewportBounds.bottom;
                    } else if (args.parameters.ModelInformationLocation == 3) {
                        location = diagram.viewportBounds.right + " " + diagram.viewportBounds.bottom;
                    }

                    var nodeData = {
                        category: "FixedText",
                        loc: location
                    };
                   diagram.model.startTransaction("node add");
                   diagram.model.addNodeData(nodeData);
                   diagram.model.commitTransaction("node add");
         
            templateMap.add("FixedText", GO(go.Node, "Spot",
                { isInDocumentBounds: false, isAnimated: false, movable: false, deletable: false, rotatable: false, selectionAdorned: false, pickable: false, selectable: false },
                new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
                GO(go.TextBlock,
                    internalHelper._getTextBlockDefaultOptions(),
                    internalHelper._getMainShapeOptions(),
                    {
                        name: "SHAPE", // resize ve rotate için gerekli
                        background: "transparent"
                    },
                    new go.Binding("text", "processTitle").makeTwoWay()
                )
            ));

Are you trying to position nodes relative to the viewport? If so, your computations are not going to work on the right side or on the bottom side – the node will be positioned outside towards the right and/or off below the viewport.

But it also depends on how you have declared the Diagram. By default the user can scroll and zoom the diagram, thereby changing the visual relationship between nodes and the viewport’s bounds. Furthermore by default the diagram will automatically scroll the nodes and links so that they are within the viewport. This is a desirable policy because most users find it confusing to show an area where nothing is because it is outside of the document bounds.

Have you seen https://gojs.net/latest/samples/absolute.html ? That probably has some features you do not want, but they are easy to remove.