How to integrate the response of the provider with marketpress

Hi guys I hope you are doing great!

I am working on integrating a payment gateway in marketpress and I am stuck at this, I really hope you can help me with this...

The payment processor allows 3 payment types, bank deposit, debit/credit card and Oxxo (which allows a buyer to pay in a grocery establishment).

Now let's say a visitor decides to choose paying with Oxxo, then the processor returns a barcode, so the buyer can print that barcode, take it to the establishment and the establishment scans it and they can make the payment..

The problem is that I haven't found the way to include that barcode that the processor returns and insert it inside the "Purchase Complete" and the "Purchase Message" that Marketpress shows and sends to the buyer...

The same happens when the visitor decides to complete the purchase with Bank deposit, the processor generates a bank account and a reference and that account and reference must be shown and added into the messages and thanks you page

Thank you very much!