let v = {
    "id": "6ccd12a3-802b-4ff6-ab6d-0f66f9df1e99",
    "mac": "a4:5e:60:f2:89:bf"
}

<VisitorModal visitor={v}/>

const VisitorModal = ({ visitor }) => {

    const [ state, setState ] = useState({
        modalOpen: false,
    })

    useEffect(() => {
        setState({
            v: visitor
        })
    })

    return (
           <Form.Input label="MAC" placeholder="mac" value={state.v.mac} />
    )
}