используйте Route вместо Router и оберните ваше приложение под Router, как показано ниже
import React, { Component } from "react";
import ReactDOM from "react-dom";
import { Route, Switch } from "react-router-dom";
import { BrowserRouter as Router } from 'react-router-dom';
const Home = () => {
return (
<div>
<h6>East or West home is The best </h6>
</div>
);
};
class App extends Component {
state = {};
render() {
return (
<div className="app">
<Route>
<Route path="/a" Component={Home}
/>
</div>
);
}
}
export default App;
ReactDOM.render(<Router><App /></Router>, document.getElementById("root"));