Update app.py

app.py

@@ -136,7 +136,7 @@ def generate_headlines(number_of_headlines, target_audience, product, temperatur
     headlines_instruction += f"Genera ahora {number_of_headlines} titulares."
 
     response = client.models.generate_content(
-        model="gemini-2.5-flash-lite",
+        model="gemini-3.1-flash-lite-preview",
         contents=headlines_instruction + "\n\nEscribe los titulares ahora.",
         config=types.GenerateContentConfig(
             temperature=temperature,