Help me in solving JS20A problem

My issue

document.body.innerHTML = ‘

CodeChef is the best!!!

after checking this when i click on submit its showing
did younadd new contents in index.js?
what can i do now?

My code

document.body.innerHTML = '<h1>CodeChef is the best!!!</h1>';

Learning course: Web development using JavaScript
Problem Link: CodeChef: Practical coding for everyone