You need path_provider package

Then try this code:

  Future<void> _deleteCacheDir() async {
    final cacheDir = await getTemporaryDirectory();

    if (cacheDir.existsSync()) {
      cacheDir.deleteSync(recursive: true);
    }
  }

  Future<void> _deleteAppDir() async {
    final appDir = await getApplicationSupportDirectory();

    if(appDir.existsSync()){
      appDir.deleteSync(recursive: true);
    }
  }