How to use the react-error-overlay/middleware function in react-error-overlay

async function start() {
  if (server) return server;
  server = express();
  server.use(createLaunchEditorMiddleware());
  server.use(express.static(path.resolve(__dirname, '../public')));

  // Configure client-side hot module replacement
  const clientConfig = webpackConfig.find(config => config.name === 'client');
  clientConfig.entry.client = [
    'react-error-overlay',
    'react-hot-loader/patch',
    'webpack-hot-middleware/client?name=client&reload=true',
  ]
    .concat(clientConfig.entry.client)
    .sort((a, b) => b.includes('polyfill') - a.includes('polyfill'));
  clientConfig.output.filename = clientConfig.output.filename.replace(
    'chunkhash',
    'hash',
  );
  clientConfig.output.chunkFilename = clientConfig.output.chunkFilename.replace(

setup(app) {
      // This lets us open files from the runtime error overlay.
      app.use(errorOverlayMiddleware());
    },
    watchOptions: {

setup: app => {
      app.use(errorOverlayMiddleware())

      if (options.server) {
        app.use(options.server)
      }
    },
    watchOptions: {