What the mistake please check this javascript code

Question

https://code.sololearn.com/W262B9oyk5mM/?ref=app

Answer 1

On lines 10 and 11, are you trying to get an element or add an event listener?

Answer 2

You don't have any elements with Id in your HTML document. But you have Javascript that reference it.

Answer 3

There was many bugs, mostly wrong selectors, i placed some comments, best is to compare your and my code.
I hope there is no more bugs, i didnt tested much
https://code.sololearn.com/W9aOz2G9pe6C/?ref=app