Full Stack Python/React developer needed for payment integration

I have a full stack React/FastAPI project for Lottery game industry. The project includes 4 apps. Back-end: FastAPI, PostgreSQL, OCR Admin website: React admin console Web app: Customer web app (React+Vite) iOS app: Customer iOS app (Expo + React Native) It is a US lottery courier / digital-fulfillment platform for NY and MA. Customers don’t buy tickets from the lottery directly in-app — they fund a wallet, order official draw/scratch tickets, and ops buy and photograph those tickets. Results sync from state lottery APIs; small prizes go to the wallet automatically. We're using Actum processiong service for bank deposit. But it was implemented in wrong way and I need to fix this. I am looking for an experienced full stack React/FastAPI developer who has previous Actum processing payment integration experience. Once we fix payment integration issue, we will work together for long-term.