&rotatewindow will rotate the contents of the VDO.Ninja window. It doesn't target any specific video, and can be used on the viewer-side, not just the sender.
This will be overridden by &forcelandscape mode, if that is used also.
You can pass 90, 180, or 270 as a value to the parameter, to rotate accordingly. The default is 90 though, if used without any value.
You might still want to use OBS to rotate instead, but if not using OBS and find the teleprompter app too cumbersome, this is a good option.
