const [searchProduct, setSearchProduct] = useState('');
    const [filteredUsers, setFilteredUsers] = useState(users);

    const onChangeSearchInput = (e) => {
        const searchItem = e.target.value;
        setSearchProduct(searchItem);

        const filteredItems = users.filter((user) => user.firstName.toLowerCase().includes(searchItem.toLowerCase()))
        setFilteredUsers(filteredItems);
    }

 <input value={searchProduct} onChange={onChangeSearchInput} type="text" placeholder="Search for products..."/>