Default behavior works for normal app restart flows. Pass options only when your app needs a specific platform behavior. 
await Restart.restartApp(
  mode: RestartMode.platformDefault,
  webOrigin: '#/home',
  forceKill: false,
  notificationTitle: 'Restart',
  notificationBody: 'Tap to reopen the app.',
);
ParameterPlatformDescription
modeAllRequested restart behavior: platformDefault, flutterEngine, process, or notificationFallback.
webOriginWebCustom origin URL for the reload. Defaults to window.origin. Supports hash strategy, for example #/home.
notificationTitleiOSTitle of the local notification shown only when mode is notificationFallback. Defaults to Restart.
notificationBodyiOSBody of the local notification shown only when mode is notificationFallback. Defaults to Tap to reopen the app.
forceKillAndroidWhen true, fully terminates the process after launching the new activity. Defaults to false. RestartMode.process enables this path automatically on Android.