I want to integrate iyzico marketplace payment gateway to phpprobid v8.1 latest version bidding script. The sample integration files exist and only need to be integrated into the existing test website. English documentation we have and one more good news is, I have already done the same model integration to my other PHP website. I can also guide you and help you to understand how the payment system works on this model. i will be next to you on any questions since I have experience with this too.