Update app.py

app.py

@@ -83,9 +83,9 @@ def user_ask(state, chatbot1, chatbot2, textbox):
     user_input = textbox
     bot1_response, bot2_response = chat_with_bots(user_input, state)
 
-    chatbot1.append(user_input,bot1_response)
+    chatbot1.append((user_input,bot1_response))
 
-    chatbot2.append(user_input, bot2_response)
+    chatbot2.append((user_input, bot2_response))
 
     # Enable voting buttons
     global upvote_btn_a,upvote_btn_b