Update app.py

app.py

@@ -36,7 +36,7 @@ def ask_with_memory(vector_store, query, chat_history=[]):
 
     from langchain.prompts import ChatPromptTemplate, SystemMessagePromptTemplate, HumanMessagePromptTemplate
 
-    llm = ChatOpenAI(model_name='gpt-3.5-turbo', temperature=0.5, openai_api_key=openai_api_key)
+    llm = ChatOpenAI(model_name='gpt-3.5-turbo', temperature=0.5, openai_api_key=OPENAI_API_KEY)
     
     retriever = vector_store.as_retriever(search_type='similarity', search_kwargs={'k': 3})