Btw, I know how to programmatically add the image, I just don't know how to add the image directly in SceneKit editor (using the drag and drop method as an example).

There was a WWDC21 session for SceneKit where they talked about adding game controllers: https://developer.apple.com/videos/play/wwdc2021/10081/ They also updated the demo Fox code so that it can run on M1 Macs now.

Fox Demo Game Code: https://developer.apple.com/library/archive/samplecode/scenekit-2017/Introduction/Intro.html#//apple_ref/doc/uid/TP40017656