Update app.py

app.py

@@ -11,7 +11,7 @@ def get_diagram_code(prompt, diagram_type, api_key):
         openai.api_key = api_key
 
         response = openai.Completion.create(
-            engine="gpt-4",
+            engine="gpt-4o",
             prompt=f"Generate a {diagram_type} diagram in Mermaid.js syntax based on the following prompt: {prompt}",
             max_tokens=500
         )