diff --git a/app/controllers/quiz_controller.py b/app/controllers/quiz_controller.py
index 6cbc082..fb23b70 100644
--- a/app/controllers/quiz_controller.py
+++ b/app/controllers/quiz_controller.py
@@ -69,7 +69,7 @@ class QuizController:
             answer_id = self.answer_service.create_answer(answer_obj)
             return make_response(
                 message="Answer submitted",
-                data={"answer_id": True},
+                data={"answer_id": answer_id},
                 status_code=201,
             )
         except ValidationError as e:
diff --git a/app/models/entities/quiz_entity.py b/app/models/entities/quiz_entity.py
index 1dd2cd4..639998f 100644
--- a/app/models/entities/quiz_entity.py
+++ b/app/models/entities/quiz_entity.py
@@ -14,6 +14,7 @@ class QuizEntity(BaseModel):
     date: Optional[datetime] = None
     total_quiz: Optional[int] = 0
     limit_duration: Optional[int] = 0
+    total_user_playing: int = 0
     question_listings: Optional[list[QuestionItemEntity]] = []
 
     class Config:
diff --git a/app/models/entities/user_answer_entity.py b/app/models/entities/user_answer_entity.py
index c03915c..23b1501 100644
--- a/app/models/entities/user_answer_entity.py
+++ b/app/models/entities/user_answer_entity.py
@@ -8,7 +8,7 @@ from .base import PyObjectId
 
 
 class UserAnswerEntity(BaseModel):
-    id: Optional[PyObjectId] = Field(alias="_id")
+    id: Optional[PyObjectId] = Field(default=None, alias="_id")
     session_id: Optional[str]
     quiz_id: str
     user_id: str
diff --git a/app/repositories/answer_repository.py b/app/repositories/answer_repository.py
index 91c7b40..8039dd4 100644
--- a/app/repositories/answer_repository.py
+++ b/app/repositories/answer_repository.py
@@ -9,7 +9,7 @@ class UserAnswerRepository:
         self.collection: Collection = db.user_answers
 
     def create(self, answer_session: UserAnswerEntity) -> str:
-        data = answer_session.model_dump(by_alias=True)
+        data = answer_session.model_dump(by_alias=True, exclude_none=True)
         result = self.collection.insert_one(data)
         return str(result.inserted_id)
 
diff --git a/app/repositories/quiz_repositroy.py b/app/repositories/quiz_repositroy.py
index 5e11625..69418b9 100644
--- a/app/repositories/quiz_repositroy.py
+++ b/app/repositories/quiz_repositroy.py
@@ -24,7 +24,7 @@ class QuizRepository:
     def get_by_ids(self, quiz_ids: List[str]) -> Optional[List[QuizEntity]]:
         object_ids = [ObjectId(qid) for qid in quiz_ids]
         cursor = self.collection.find({"_id": {"$in": object_ids}})
-        datas = list(cursor)  
+        datas = list(cursor)
         print(datas)
 
         if not datas:
@@ -62,6 +62,12 @@ class QuizRepository:
         )
         return result.modified_count > 0
 
+    def update_user_playing(self, quiz_id: str, total_user: int) -> bool:
+        result = self.collection.update_one(
+            {"_id": ObjectId(quiz_id)}, {"$set": {"total_user_playing": total_user}}
+        )
+        return result.modified_count > 0
+
     def delete(self, quiz_id: str) -> bool:
         result = self.collection.delete_one({"_id": ObjectId(quiz_id)})
         return result.deleted_count > 0
diff --git a/app/services/answer_service.py b/app/services/answer_service.py
index daef84a..6f5f4f9 100644
--- a/app/services/answer_service.py
+++ b/app/services/answer_service.py
@@ -29,6 +29,11 @@ class AnswerService:
         if not user_data:
             raise ValidationException(message="user is not registered")
 
+        total_quiz_played = quiz_data.total_user_playing + 1
+        self.quiz_repository.update_user_playing(
+            quiz_id=quiz_data.id, total_user=total_quiz_played
+        )
+
         question_map = {q.index: q for q in quiz_data.question_listings}
 
         answer_item_Entity = []
@@ -91,8 +96,7 @@ class AnswerService:
             total_score=total_score,
         )
 
-        self.answer_repository.create(answer_entity)
-        return True
+        return self.answer_repository.create(answer_entity)
 
     def update_answer(self, answer_id, answer_data):
         return self.answer_repository.update(answer_id, answer_data)