Screen.orientation api error?

When testing out this code in the api:
[https://docs.unity3d.com/ScriptReference/Screen-orientation.html][1] Error on this line:
Screen.orientation = ScreenOrientation.LandscapeLeft; Error:
> Assets/DeviceChange.cs(186,40): error CS0117: `ScreenOrientation' does not contain a definition for `LandscapeLeft' Any ideas? I am copying the code from the api so I am confused why it doesn't work. [1]: https://docs.unity3d.com/ScriptReference/Screen-orientation.html