razorpay/react-native-razorpay ? reverse-engineered prompt

Build me a React Native payment wrapper for Razorpay that works on both iOS and Android.

I want to be able to install it in a React Native app, pass in payment details like amount, currency, customer name, email, phone, and theme color, then open the Razorpay checkout screen from JavaScript. It should return a promise so my app can tell the difference between a successful payment and a failed one, and I can show the payment id or an error message.

Please include a simple sample app that shows how to trigger the payment flow from a button, plus clear setup steps for linking on iOS and Android. If there are any native setup steps or permissions needed, make those easy to follow too. Keep it focused on the checkout wrapper and make sure the package is ready for real mobile app use.