//Here is the code

const [products, setProducts] = useState({})

const { quantity } = products;

const handleRestock = (e) => {
    e.preventDefault();

    if (quantity) {
        const addedQuantity = e.target.quantity.value;
        console.log(addedQuantity);
        const updatedQuantity = parseInt(quantity) + parseInt(addedQuantity);
    }
}