That's some admirable persistence by the author... I gave up on Flutter (for now) right after installing, having to accept (and supposedly read first) about 10 licenses during the process and then failing to start basically the default app in the Android emulator with obscure error messages. What a terrible UX developers have to put up with these days... At least it was funny to let Android Studio analyze the code (the default app), yielding these:
FlutterBinaryMessenger.h
Typo: In word 'FLUTTERBINARYMESSENGER'
Typo: In word 'Implementated'
Typo: In word 'commuication'
Doesn't look like people actually use all these features much.