Overlay text on a diagram that stays fixed as viewport is moved

Is it possible to overlay text on a diagram that stays fixed as viewport is moved?

We attempted to create a template that is unmovable while adjusting the x, y coordinates based on viewportBoundsChanged listener with diagram.viewportBounds variables, but the nodes are moving around and not staying fixed in the diagram.

Our implementation of our template:

export const someTemplate = makeGraph(
  { movable: false },
      margin: 5,
      stroke: "white",
      textAlign: "center",
      editable: false,
      font: "20px Segoe-UI, sans-serif",
    new go.Binding("text", "key"),
    new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),

Is there an easier way to do this? Thank you in advance!

So you must have already read https://gojs.net/latest/intro/legends.html
And in particular: https://gojs.net/latest/intro/legends.html#StaticParts

Does it have to be made in GoJS? Could you just implement it as HTML that is in front of the HTMLDivElement that hosts the Diagram?

This answered our question. Thank you!