Instead of being restricted to the default fields in your Paythen payment pages, you can now ask for any additional info you need from customers with seamlessly integrated custom fields. Custom fields add much more flexibility to how you can use Paythen. Combined with url parameters and the ability to make custom fields invisible, you get powerful tracking and pre-filling functionality that makes using Paythen even better.
Just switch on the custom fields toggle in your plan creation screen to start. Read more about using custom fields here.