App.js

// Example with Redux Toolkit
import React from 'react';
import {createAction, createReducer, configureStore} from 'redux-toolkit';
import {Provider, useSelector, useDispatch} from 'react-redux';

const initialState = {counter: 0};

const increment = createAction('INCREMENT');

const reducer = createReducer(initialState, {
  [increment.type]: state => ({...state, counter: state.counter + 1})
});

const store = configureStore({reducer: counter});

const App = () => {
  return (
    <Provider store={store}>
      <Counter />
    </Provider>
  );
}

const Counter = () => {
  const counter = useSelector(state => state.counter);
  const dispatch = useDispatch();
  
  return (
    <>
      <button onClick={() => dispatch(increment)}>Click me</button>
      <p>You clicked me {counter} times</p>
    </>
  );
};