How to make setAttribute only work on child elements from Div Id?

Question

This is my code.
Sorry, my English is bad 🙏
https://code.sololearn.com/WXDcLT0aejH3/?ref=app

Answer 1

var inp1 = document.querySelectorAll("#demo input")[0];
var inp2 = document.querySelectorAll("#demo input")[1];

https://code.sololearn.com/W0GKiqHQJ1Fj/?ref=app

Answer 2

Thanks 🙏😀