To receive a callback after successful or failed payment, you have to specify to which URL it will be sent.
- You have to specify the URL under your E-shop settings by clicking on the e-shop.
 
- In the “Payments” section, you have to fill the “Callback Notification URL”.
 
- After each payment you will receive a callback with 
payment_reference and order_reference

 
- When you receive a callback you can request payment status using 
payment_reference, by using GET /payments/:payment_reference endpoint (more detailed information can be found in the API documentation, section Callback Notification)