ChildCaller.js

const RandomNumberGenerator = () => {

    const [number, setNumber] = useState(Math.random());
    const regenerate = () => {
        setNumber(Math.random());
    }
    const RandomNumber = () => {
        return number;
    }
    return { regenerate, RandomNumber };

}

export default function Home() {
	const { RandomNumber, regenerate } = RandomNumberGenerator();
	return (
		<div>
			<RandomNumber/>
			<button onClick={regenerate}>Re-generate!</button>
		</div>
	)
}