Input validation for react.
Use formik, yup, mui.
Formik's sample. (https://formik.org/docs/examples/with-material-ui)
But not working.

1. Modify import mui path.

import Button from '@mui/material/Button';
import TextField from '@mui/material/TextField';

2. Add onBlur method. Because not working 'formik.touched'.

onBlur={formik.handleBlur}

3. Remove yup.string() contents.

  email: yup
    .string()

https://sig03.medium.com/formik-yup-mui-샘플-예제-동작-안-하는-부분-수정-43dafd55a919
https://duckgugong.tistory.com/218