Mini Browser shows: Missing cw0

[Vincenzo]

import React from "react"
import ReactDOM from "react-dom"

function TestInsertion() {
    <ul>
        <li>simplify</li>
        <li>money</li>
        <li>fun</li>
    </ul>
}

ReactDOM.render(<TestInsertion />, document.getElementById("root"))

I used this code and the Mini Browser show this error.
What can I do to solve it?

[Vincenzo]

I forgot to put return ( before ul and at the end of /ul