I am using Unity version 6000.0.34f1 and I'm trying to create a World Space UI with the UI Toolkit. According to the official Unity 6 documentation, this should be straightforward: "To create a World Space UI, set the render mode of the Panel Settings asset to World Space." The Unitiy3D documentation page (Create a World Space UI) also confirms that my version is supported.
However, when I select my Panel Settings asset in the Inspector, the Render Mode field is absent. Here is a screenshot of my Panel Settings inspector:

I have already tried to solve this in a few ways:
- Accessing via C# Script: I tried to set the mode programmatically:
var uiDocument = GetComponent<UIDocument>();
// This line causes a compile error
uiDocument.panelSettings.renderMode = PanelRenderMode.WorldSpace;
- Checking Project Settings: I checked Edit > Project Settings > UI Toolkit, thinking the feature might have been moved to an experimental flag, but there are no options there to enable World Space rendering.
My question is:
How can I set a UI Toolkit panel to World Space in this specific version of Unity? Am I missing a package dependency, or has the workflow changed completely and the documentation is not yet updated?
Any help or insight would be greatly appreciated. Thank you