UniFi Paystack Captive Portal Integration

I’m building an external captive portal that sits in front of my Ubiquiti UniFi controller. Once a customer pays through Paystack, the system must instantly create a username and password, push the right bandwidth limits to UniFi via its API, and save the full transaction details for later review... (Budget: $30 - $250 USD, Jobs: API, HTML, MySQL, Node.js, PHP, Python, Ubiquiti, Website Design)