Help in JS

Question

Was trying to change background color of table using js but failed to do so

https://code.sololearn.com/Wm5CWhiI2qw0/?ref=app

Answer 1

Delete onclick=ch() and type="button";

//Use
onload = ()=>{
//const btn = document.getElementById('btn');

btn.addEventListener('click', function onClick(event) {
const box = document.getElementById('tb');

box.style.backgroundColor = 'red';

});
}

Or:
function ch(){
tb.style.backgroundColor='red';
}

ES6:
ch=()=>tb.style.backgroundColor='red';

Answer 2

You gave the button the id "btb" but in the code you use "btn"