Update app.py

app.py

@@ -122,7 +122,7 @@ Convert the Invoice Date to the specified dd-MMM-yyyy format.
 Use the correct currency and amounts for each invoice field.
 For each line item, provide the Description, Tax Percentage, Tax Amount, and Amount.
 If certain values are missing or not applicable, leave them empty or set them as null where necessary.
-This JSON format will be used to store and manage invoices in a structured and uniform way."""
+This JSON format will be used to store and manage invoices in a structured and uniform way. Please ensure only return JSON format. No extra content should not provide."""
     try:
         response = openai.ChatCompletion.create(
             model="gpt-4o-mini",