Hello. The external id of the payment method in the box
https://prnt.sc/ozl78i is passed in the priceType field
If the process does not have a payment method specified or this payment method does not have an external ID, an empty string will be passed
As can be seen from their documentation, this field is optional and it is quite possible to pass an empty string to it. Perhaps you need to set the main type of payment in the relog system?