Apple Pay with SwiftUI

The PKPaymentAuthorizationController class performs the same role as the PKPaymentAuthorizationViewController class, but it does not depend on the UIKit framework. This means that the authorization controller can be used in places where a view controller cannot (for example, in watchOS apps or in SiriKit extensions).

Code Block 
let request = PKPaymentRequest()
request.paymentSummaryItems = ...
let controller = PKPaymentAuthorizationController(paymentRequest: request)
controller.delegate = self
controller.present { [weak self] presented in
   // Apple Pay presented from scene window
}

Code Block swift
import SwiftUI
import UIKit
import PassKit
struct PaymentButton: View {
    var body: some View {
        Button(action: {
            /* Your custom payment code here */
        }, label: { EmptyView() } )
            .buttonStyle(PaymentButtonStyle())
    }
}
struct PaymentButtonStyle: ButtonStyle {
    func makeBody(configuration: Self.Configuration) -> some View {
        return PaymentButtonHelper()
    }
}  
struct PaymentButtonHelper: View {
    var body: some View {
        PaymentButtonRepresentable()
            .frame(minWidth: 100, maxWidth: 400)
            .frame(height: 60)
            .frame(maxWidth: .infinity)
    }
}
extension PaymentButtonHelper {
    struct PaymentButtonRepresentable: UIViewRepresentable {
     
        var button: PKPaymentButton {
            let button = PKPaymentButton(paymentButtonType: .buy, paymentButtonStyle: .black) /*customize here*/
            button.cornerRadius = 4.0 /* also customize here */
            return button
        }
     
        func makeUIView(context: Context) -> PKPaymentButton {
            return button
        }
        func updateUIView(_ uiView: PKPaymentButton, context: Context) { }
    }
}

Code Block swift
import SwiftUI
import iPaymentButton
struct ContentView: View {
    var body: some View {
        iPaymentButton(type: .support, style: .whiteOutline, action: {
             /* Add your custom payment code here */
        })
    }
}