Displaying username with AmplifyGreetings

I have a react app being developed with the Amazon Amplify framework. As per the documentation I am trying to retrieve my username (that I have specified during the signup process) before the Signout button. The document is not clearly instructed on how to display my username, as the <AmplifyGreetings> component puts a dummy attribute of username. Could someone guide me on how to do that?

Code: App.js

import React from "react";
import { withAuthenticator, AmplifyGreetings } from "@aws-amplify/ui-react";
class App extends React.Component {
  render() {
    return (
      <div>
        <AmplifyGreetings username="retrieve your username here"></AmplifyGreetings>
      </div>
    );
  }
}

export default withAuthenticator(App);

This is what my output looks like.