How to define RTL for some part, not all part?

I want to create an application that the intro app of my app to be LTR and other parts to be RTL. I found some code for RTL:

  localizationsDelegates: [
    GlobalCupertinoLocalizations.delegate,
    GlobalMaterialLocalizations.delegate,
    GlobalWidgetsLocalizations.delegate,
  ],
  supportedLocales: [
    Locale("fa", "IR"), // OR Locale('ar', 'AE') OR Other RTL locales
  ],
  locale: Locale("fa", "IR")

But it is used for all parts, not some parts, please help me. I used this package for my app intro