First, we have to specify a loading indicator, which will be shown when our lazily-loaded component is loading. In our example, we are going to wrap the UserBar component with React Suspense.

Edit src/App.js, and replace the <UserBar /> component with the following code:

                    <React.Suspense fallback={"Loading..."}>
                        <UserBar />
                    </React.Suspense>

Now, our app is ready for implementing lazy loading.