I cant get elements by ID. Pls, help

Question

So,
https://code.sololearn.com/WWEt0fi766Jd/?ref=app

I cant get elements and I don't understand why.

Answer 1

JS loads first. So when you search for the id s of the elements, you will not find any. Cut the whole js and paste it in HTML, inside a script tag.
Search on google about window.onload(){}

Answer 2

Thank you, I added code to onload handler and it works now