React tutorial appears to be broken

The beginners Tic Tac Tutorial produces errors when the code is entered into Codepen.io
There is no way to get Codepen to register the code as correct except when copy pasting the end demo file.
I'm more muddled by the concepts of react after this tutorial rather than informed and practiced by following it.
Rather better way would be to 1) one small module that lets you practice prop passing 2) one small module that lets you define the js code that will use the render method and so forth. The current tutorial seems a stream of thought and as a whole incoherent as a demonstration of reacts strengths.

Comece reproduzindo o Tic Tac Tutorial para iniciantes no CodePen.io e documente os erros que ocorrem quando o código é inserido incrementalmente. Está concluído quando o tutorial funciona no CodePen e suas etapas apoiam claramente a prática de passagem de props e do uso do método render.