If you like to pilot the refund payment flow, you need to follow the next steps
1: Enable the setting on the Sales Location.
2: PAY needs to enable in pilot all terminals Manualy, send email to support@pay.nl with in the title REFUND-POS Pilot
3: You need to switch to the multicore
3A: Click 5 times on the TH code to enable the Developer Mode
3B: Change the CORE to MULTI for KEYLOADING and PROCESSING