Next.js Goaffpro Affiliate Integration 24 hr turn around

I run a live Next.js site on Railway.app and I already have a Goaffpro account waiting to be hooked in. I want the full affiliate toolkit—link tracking, discount-code creation, and the built-in reporting dashboard—working seamlessly for my current users without losing any of their data... (Budget: $250 - $750 USD, Jobs: Affiliate Marketing, API, Google Chrome, JavaScript, jQuery / Prototype, Next.js, PHP, Web Development)