Fix field name

app.py

@@ -133,7 +133,7 @@ def create_app(config_name):
             }
         }
 
-        message = {"title": "Subscription Successful", "body": "Thank you for subscribing!"}
+        message = {"title": "Subscription Successful", "message": "Thank you for subscribing!"}
         success = send_push_notification(subscription_info, message, vapid_key)
         
         return jsonify(success=success, message=vapid_key.private_key)