changed append

app.py

@@ -9,7 +9,7 @@ def respond(message, history):
     if history:
         messages.extend(history)
 
-    message.appened({"role": "user", "content": message})
+    message.append({"role": "user", "content": message})
 
     response = client.chat_completion(messages, max_tokens = 100)