UPS Rates & PayPal Integration

My e-commerce app already runs on a React front-end with a PHP-based admin panel. I now need two things completed end-to-end:

• UPS Live Rates – show real-time shipping costs in the React checkout using my existing UPS credentials, limited to “Standard Ground Shipping” and “2nd Day Air”. Rates must update dynamically based on weight, destination and any other UPS requirements, and store the chosen service in the order data that the PHP admin later displays.

• PayPal – add Express Checkout plus PayPal Credit to the same checkout flow. The PHP back office should log each transaction ID and allow me to update or refund payments directly from the panel.

I will supply the live API keys for both providers as soon as we start. Everything needs to run in production mode, with test transactions first to confirm:

– UPS returns the correct prices for various U.S. ZIP codes
– PayPal completes, cancels and refunds without errors

Code should be cleanly commented so my team can maintain it later. Let me know your estimated timeline and any questions about the current codebase.