install react hook form

npm install react-hook-form
npm install react-hook-formimport React from 'react';import { useForm } from 'react-hook-form'; function App() {  const { register, handleSubmit, errors } = useForm(); // initialise the hook  const onSubmit = (data) => {    console.log(data);  };   return (    <form onSubmit={handleSubmit(onSubmit)}>      <input name="firstname" ref={register} /> {/* register an input */}            <input name="lastname" ref={register({ required: true })} />      {errors.lastname && 'Last name is required.'}            <input name="age" ref={register({ pattern: /\d+/ })} />      {errors.age && 'Please enter number for age.'}            <input type="submit" />    </form>  );}