I am very new to SceneKit and have been following online tutorials. When I use the scene editor and produce objects in the scene editor, when I run the app, all I can see is a blank screen. Am i missing something here?

I’m very new to iOS development and have a ‘free’ account while I learn the ins and outs of Xcode. I’m was running Xcode 13.3 under OS 12.4 and live preview on playgrounds stopped showing anything. When I checked out my account I am told that my session has timed out and I need to login. I put I my Apple ID and nothing happens. I’m missing something here, but I don’t know what. HELP!!!