Increment.js

import React, { useState } from 'react';
import Button from '@material-ui/core/Button';
import AddIcon from '@material-ui/icons/Add';
import '../node_modules/bootstrap/dist/css/bootstrap.min.css';
import '../node_modules/bootstrap/dist/js/bootstrap.bundle';

const Calculator = () => {
    const [add, setAdd] = useState(0);
    const increment = () => {
        setAdd(add + 1);
    }
    return (
        <>
            <div className="container">
                <h1>{add}</h1>
                <Button size="large" variant="contained" className="btns" onClick={increment}>
                    <AddIcon className="colorButton" />
                </Button>
            </div>
        </>
    );
}

export default Calculator;