Update app.py

app.py

@@ -101,7 +101,7 @@ class PDFChat:
         try:
             response = openai.ChatCompletion.create(
                 # model="gpt-4-turbo",
-                model="gpt-4o" ,
+                model="gpt-4o-mini" ,
                 messages=messages
             )
             response_text = response.choices[0].message['content']