aws4.js

const PrivateRoute = ({component: Component, ...rest}) => {
  return(
    <Route {...rest} render={props => (
      localStorage.getItem('isLogged') === 'true' ?
        <Component {...props} />
          : <Redirect to="/login" />
    )}
    />
  )
}

...

<BrowserRouter>
  <Switch>
    <Route path='/login' component={LogInPage}/>
    <PrivateRoute path="/landing" component={LandingPage} />
  </Switch>
</BrowserRouter>