iOS Core SDK

// Complete payment in ~20 lines of code
let paymentParam = PayUPaymentParam(
    key: "merchantKey",
    transactionId: "TXN123",
    amount: "100.00",
    productInfo: "Product",
    firstName: "John",
    email: "[email protected]",
    phone: "9876543210",
    surl: "https://yoursite.com/success",
    furl: "https://yoursite.com/failure",
    environment: .test
)

// One line to show payment UI
PayUCheckoutPro.open(on: self, paymentParam: paymentParam, config: nil, delegate: self)

// SDK handles everything: UI, validation, bank pages, response

// You need to build:
// 1. Payment method selection UI
// 2. Card input form with validation
// 3. Bank selection dropdown
// 4. UPI ID input field
// 5. OTP handling UI
// 6. Loading states
// 7. Error handling UI
// 8. Success/failure screens

// Then use SDK to create payment request
let paymentParams = PayUModelPaymentParams()
// ... configure all parameters ...

let createRequest = PayUCreateRequest()
createRequest.createRequestWithCardForMerchant(
    withDetails: paymentParams,
    cardNumber: userEnteredCardNumber,  // From your UI
    cvv: userEnteredCVV,                // From your UI
    expiryYear: userSelectedYear,       // From your UI
    expiryMonth: userSelectedMonth,     // From your UI
    nameOnCard: userEnteredName,        // From your UI
    storeCardToken: 0,
    withCompletionBlock: { (request, postParam, error) in
        // Load in WebView/Custom Browser
        // Handle response
        // Show result in your UI
    }
)

let config = PayUCheckoutProConfig()
config.primaryColor = UIColor(hex: "#FF6B00")
config.merchantLogo = UIImage(named: "your_logo")
config.paymentModesOrder = [.upi, .cards, .netBanking, .emi]