Why doesn't the code work (the button that lowers the page down)?

Question

React

I have code where one component is functional and the other is class. I decided that I would make both of them class components, so I decided to remake the App functional component into a class one. But the code doesn't work. What is the reason?
Original (working code):
https://jsfiddle.net/nathan111777/cvs5xdrb/2/
What I redid:
https://jsfiddle.net/nathan111777/6yxdsozf/22/

Answer 1

class App extends React.Component
you have a Russian letter in the word class along the way, rewrite it :D