// const h1 = document.createElement("h1")
// h1.textContent = "Hello world"
// h1.className = "header"
// console.log(h1)

ReactDOM.render(<h1>This is JSX</h1>, document.getElementById("root"))

▲

"You are using the in-browser Babel transformer. Be sure to precompile your scripts for production - https://babeljs.io/docs/setup/"

-9:39