We're happy to help answer your question. Some of our API Products have the option to add a callback configuration (e.g. Visa Transaction Controls). To setup the endpoint URL for the notification callback API: Go to the configurations of the project that you have created. Click “Add Callback Configuration”. Then you will see the option to add the domain and the path. When you create a Visa Transaction Controls project on dashboard it takes data from your app, which sends the callback notification and the parameters are system generated as it is a set template.