Find a way to connect the payment system to the website

Need a specialist to connect a payment system to the SMM service website

We are looking for a person (preferably with experience working on similar projects) who can help connect a payment system to a website promoting on social networks (likes, followers, views, etc.).

The website operates similarly to https://nakrutochka.com/ — a payment gateway implementation is needed for accepting payments for automated SMM services.

We have a registered sole proprietorship with the appropriate activity code. We tried to connect payment systems ourselves (4 different services) — received refusals without explanations. We need a specialist who can either:
– successfully integrate a payment system that works with such services,
– or propose a legal workaround (for example, through intermediaries or alternative gateways).