useEffect

Define a cleanup function inside the useEffect return statement
To handle cleanup for a subscription in useEffect, you should define a cleanup function inside the return statement of the useEffect callback. React will automatically call this cleanup function when the component unmounts or before re-running the effect.
Use the return statement to call the cleanup function
Manually unsubscribe in the component's componentWillUnmount
There's no need to handle cleanup for subscriptions in useEffect