Payment gateway integration

Hello, I'm looking for an expert coder to help me with the payment gateway integration software I need. The platform needs to work with WordPress, Magento and Shopify - no problem! I already have an existing payment gateway that I'd like to use, and I'll need it to accept debit cards, credit cards, UPI, and Payout as payment methods. It's an important project, so I need someone who is reliable and skilled. If you have the expertise and experience to get the job done, please apply!