Update app.py

app.py

@@ -18,7 +18,7 @@ def python_tutor_bot(user_input):
 
     # Create a completion request
     response = openai.ChatCompletion.create(
-        model="gpt-3.t-turbo",
+        model="gpt-3.5-turbo",
         messages=[
             {
                 "role": "system",