chatbot memory problem for langchain using ConversationalRetrievalChain

Question

i have build a chatbot on custom data using langchain, but the chatbot can not remember my previous questions, I found it difficult with the ConversationalRetrievalChain.

My code is as below:

`class MyBot(ActivityHandler):
    def __init__(self, conversation_state: ConversationState):
        self.conversation_state = conversation_state
        self.session_accessor = self.conversation_state.create_property("Session")
       
            
        # Data loader
        loader = CSVLoader(file_path="data.csv", encoding="utf-8", csv_args={'delimiter': ','})
        data = loader.load()

        # OpenAI API key
        openai_api_key = os.environ.get('OPENAI_API_KEY')

        # Initialize OpenAIEmbeddings
        embeddings = OpenAIEmbeddings(openai_api_key=openai_api_key)

        # Initialize FAISS for the vector database
        vectors = FAISS.from_documents(data, embeddings)
        

        # Initialize the ConversationalRetrievalChain
        self.chain = ConversationalRetrievalChain.from_llm(
            llm=ChatOpenAI(temperature=0.5,request_timeout=100,  model_name='gpt-4o', max_tokens= 2048, openai_api_key=openai_api_key),
            retriever=vectors.as_retriever(), combine_docs_chain_kwargs={"prompt": QA_PROMPT}
        )    

def run_chain(self, chat_history, question):
        return self.chain.run({'chat_history': chat_history, 'question': question})

    
    

    async def get_response(self, user_message, turn_context: TurnContext):
    # Retrieve the session for the current user
        session = await self.session_accessor.get(turn_context, lambda: {"messages": [{"role": "system", "content": "You work for and M company answer any questions related to the company."}]})

    # Add user message to the session
        session["messages"].append({"role": "user", "content": user_message})

        response = self.run_chain("", user_message)

        ai_response = response  # Use response directly

    # Add AI response to the session
        session["messages"].append({"role": "assistant", "content": ai_response})

        # Save the updated session
        await self.conversation_state.save_changes(turn_context)

        return ai_response`

I just want my chatbot to remember my previous question like chatgpt.

thanks in advance!

integrate the memory within the chatbot