Update app.py

app.py

@@ -77,7 +77,7 @@ class SpyAgent(BasicAgent):
             api_key=os.getenv('API_KEY')
         )
         completion = client.chat.completions.create(
-            model="gpt-4o-mini",
+            model=os.getenv('MODEL_NAME'),
             messages=[
                 {'role': 'system', 'content': 'You are a helpful assistant.'},
                 {'role': 'user', 'content': prompt}