How to send form data from react to express

const url = localhost:4000/api/users/register;
const usersData= [];

let getData = () => {
axios.get(url)
   .then(res => usersData.push(res.data))
   .catch(err => console.log(err.data))
}

const reactData = [{ id: 1, name:' Tom'}, { id: 2, name:' Sarah'}];
const url = localhost:4000/api/users/register;

let sendData = () => {
axios.post(url, reactData)
   .then(res => console.log('Data send'))
   .catch(err => console.log(err.data))
}