2 years later same issue:

"In the iPad OS Kasa app, when you launch the app, you are able to fully navigate around the app in landscape mode. Great. But, when you go into the camera view and then select a camera to view live in full screen, the app locks you into that screen. There is no back button, you just have to rotate the ipad. Why am I complaining about such a small oversight? because many ipad users keep their ipads in a keyboard case. So, in order to use this app, which is otherwise pretty good for a hardware manufacturer, I have to remove my ipad from its case, unplug it, rotate it, then place it back after I leave that view. It ruins a great experience. "