Update app.py

app.py

@@ -124,7 +124,7 @@ async def start():
 
 
 @cl.on_message
-async def process_response(res):
+async def process_response(message):
     chain = cl.user_session.get("chain")
     cb = cl.AsyncLangchainCallbackHandler(
         stream_final_answer=True, answer_prefix_tokens=["FINAL", "ANSWER"]