one_ui_flutter_app/lib/js/initial_route.dart

import 'package:js/js.dart';
// ignore: avoid_web_libraries_in_flutter
import 'dart:html' as html;

@JS('fx_initial_route')
external String fxInitialRoute();

String? getToken() {
  return html.window.localStorage['token'];
}

String? getUser() {
  return html.window.localStorage['user'];
}