update_middlewares.dart

// Other code
GetPage(
      name: AppLinks.DASHBOARD, 
      page: () => Dashboard(), 
      middlewares: [
        // Add here
        AuthGuard(),
      ],
      children: [
        GetPage(
          name: AppLinks.PRODUCTS,
          page: () => Products(),
        ),
        GetPage(
          name: AppLinks.FAVORITES,
          page: () => Favorites(),
        ),
        GetPage(
          name: AppLinks.ORDERS,
          page: () => Orders(),
        ),
    ]),