Update app.py

app.py

@@ -123,7 +123,7 @@ async def main(message):
     chain = cl.user_session.get("chain")  # type: ConversationalRetrievalChain
     cb = cl.AsyncLangchainCallbackHandler()
 
-    res = await chain.acall(message, callbacks=[cb])
+    res = await chain.acall(message.content, callbacks=[cb])
     answer = res["answer"]
     source_documents = res["source_documents"]  # type: List[Document]