Change the boolean value onclick and save to secured storage flutter

Question

class Lessons {
  final int? id;
  final String? title;
  final List<Resources> resources;
  Lessons({
    required this.id,
    required this.title,
    required this.resources,
  });
}

class Resources extends Equatable {
  final int? id;
  final String? question;
  final String? answer;
  bool? bookmark;
  Resources({
    required this.id,
    required this.question,
    required this.answer,
    required this.bookmark,
  });
}

//storing in secured storage
    static Future<void> setLessonData(jsonData) async {
        final jsonDataEncoded = jsonEncode(jsonData);
        await storage.write(key: lessonsData, value: jsonDataEncoded);
      }
    
      static Future<DataResponse<List<Lessons>>> getLessonDataFromLocal() async {
        final jsonModel = await storage.read(key: lessonsData);
        final jsonData = jsonDecode(jsonModel.toString());
        final items = List.from(jsonData["lessons"]);
    
        lessonsList = items.map((e) => Lessons.fromJson(e)).toList();
        return DataResponse.success(data: lessonsList);
      }

-these are my models, and have saved them using the secured storage flutter. How do i change just the bookmark and save it to secured storage?

i was able to change the bookmark but was unable to save it dynamically to secured storage.