AddStock.jsx

import React, { Fragment } from 'react'

const AddStock = ({ handleAddStock }) => {
  const [available, setAvailable] = useState(0)
  return (
    <Fragment>
      <input
        onChange={event => setAvailable(event.target.value)}
        value={available}
      />
      <button onClick={handleAddStock(available)}>
        Add
      </button>
    </Fragment>
  )
}
      
export default AddStock