Please why and how is there an error on my JavaScript?

Question

I'd need all the help I can get. Thanks!

https://code.sololearn.com/WSpqK3mt2wdm/?ref=app

Answer 1

Search for similar questions please ,

Script getting loaded before html so the elements don't exists yet,use this to avoid that condition

window.onload=function(){
Js code goes here
}