trunk-server/frontend/src/index.js

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux'
import { Route, Switch } from 'react-router' // react-router v4/v5
import { ConnectedRouter } from 'connected-react-router'
import configureStore, { history } from './app/configureStore'

import App from './App';


const store = configureStore(/* provide initial state if any */)

ReactDOM.render(
  <Provider store={store}>
    <ConnectedRouter history={history}> { /* place ConnectedRouter under Provider */ }
      <> { /* your usual react-router v4/v5 routing */ }
        <Switch>
          <Route exact path="/" render={() => (<App />)} />
          <Route render={() => (<div>Miss</div>)} />
        </Switch>
      </>
    </ConnectedRouter>
  </Provider>,
  document.getElementById('root')
)