remix-project/apps/remix-ide/src/index.tsx

// eslint-disable-next-line no-use-before-define
import React, { Suspense, lazy } from 'react'
import ReactDOM from 'react-dom'
import AppComponent from './app'
// eslint-disable-next-line no-unused-vars
const RemixApp = lazy(() => import ('@remix-ui/app'));

const appComponent = new AppComponent()
appComponent.run()

ReactDOM.render(
  <React.StrictMode>
    <Suspense fallback={<div>Loading...</div>}>
      <RemixApp app={appComponent} />
    </Suspense>
  </React.StrictMode>,
  document.getElementById('root')
)