Connect to Portmone Payment on OpenCart

Hello, dear developer. There is an online store that runs on the Open Cart version (ocStore 1.5.5.1.2) in the process of placing an order, modules are used: "Order and registration Simple", as well as the "Payment Plus" module for choosing a payment method.
You need to connect the possibility of online payment through the portmone.com service to the site. Detailed TZ and instructions from the service portmone attach.

I expect a price and a deadline from you.