Update app.py

app.py

@@ -78,7 +78,7 @@ def generate_questions_with_retry(knowledge_material, question_type, cognitive_l
     retries = 0
     while retries < max_retries:
         try:
-            response = client.chat.completions.create(
+            response = openai.ChatCompletion.create(
                 model="gpt-4o-mini",
                 messages=[
                     {"role": "system", "content": "You are a helpful assistant for generating exam questions."},