Update app.py

app.py

@@ -14,7 +14,7 @@ class ChatBot:
         self.history.append({"role": "user", "content": prompt})
         
         completion = self.client.chat.completions.create(
-            model="gpt-4", # NOTE: feel free to change it to gpt-4o
+            model="gpt-3.5-turbo", # NOTE: feel free to change it to gpt-4, or gpt-4o
             messages=self.history
         )