I have a VR game built with default Unity UI system.
Canvas Render Mode is set to World Space.
My UI has tabs, buttons, scroll views, custom controls made as prefabs.
Can UI Toolkit can be used in VR? I use Unity 2020.3 LTS
Are you referring to UI Toolkit or UGUI?
If you are referring to UGUI, this forum is the one to use.
UI Toolkit doesn’t support World Space UI directly at the moment. You would need to render to a texture and place said texture in world space manually.