Implementing Sign in with Apple

import AuthenticationServices

class LoginViewController: UIViewController {
    func setupProviderLoginView() {
        let authorizationButton = ASAuthorizationAppleIDButton(
            type: .signIn,
            style: .whiteOutline
        )

        authorizationButton.addTarget(
            self,
            action: #selector(handleAuthorizationAppleIDButtonPress),
            for: .touchUpInside
        )

        self.addSubview(authorizationButton)
    }

    @objc func handleAuthorizationAppleIDButtonPress() {
        let appleIDProvider = ASAuthorizationAppleIDProvider()
        let request = appleIDProvider.createRequest()
        request.requestedScopes = [.fullName, .email]

        let authorizationController = ASAuthorizationController(authorizationRequests: [request])
        authorizationController.delegate = self
        authorizationController.presentationContextProvider = self
        authorizationController.performRequests()
    }
}

// MARK: - Sign in with Apple
extension LoginViewController: ASAuthorizationControllerDelegate,
                               ASAuthorizationControllerPresentationContextProviding {
    func presentationAnchor(for controller: ASAuthorizationController) -> ASPresentationAnchor {
        return self.view.window!
    }

    func authorizationController(
        controller: ASAuthorizationController,
        didCompleteWithAuthorization authorization: ASAuthorization
    ) {
        switch authorization.credential {
        case let appleIDCredential as ASAuthorizationAppleIDCredential:
            // Create an account in your system.
            let userIdentifier = appleIDCredential.user
            let fullName = appleIDCredential.fullName
            let email = appleIDCredential.email
            let JWTToken = appleIDCredential.identityToken
            let authCode = appleIDCredential.authorizationCode

            dump(appleIDCredential)
            // Close login window.

        case let passwordCredential as ASPasswordCredential:
            // Sign in using an existing iCloud Keychain credential.
            let username = passwordCredential.user
            let password = passwordCredential.password

            print(passwordCredential)
            // Close login window

        default:
            break
        }
    }

    func authorizationController(controller: ASAuthorizationController, didCompleteWithError error: Error) {
        // Handle error.
        print("Something went wrong", error)
    }

    func performExistingAccountSetupFlows() {
        // Prepare requests for both Apple ID and password providers.
        let requests = [ASAuthorizationAppleIDProvider().createRequest(),
                        ASAuthorizationPasswordProvider().createRequest()]

        // Create an authorization controller with the given requests.
        let authorizationController = ASAuthorizationController(authorizationRequests: requests)
        authorizationController.delegate = self
        authorizationController.presentationContextProvider = self
        authorizationController.performRequests()
    }
}

import SwiftUI
import AuthenticationServices

struct ContentView: View {
    var body: some View {
        SignInWithAppleButton(.signIn) { request in
            request.requestedScopes = [.fullName, .email]
        } onCompletion: { result in
            switch result {
            case .success(let authorization):
                if let userCredential = authorization.credential as? ASAuthorizationAppleIDCredential {
                    dump(userCredential)
                }

            case .failure(let error):
                print("Could not authenticate: \(error.localizedDescription)")
            }
        }
        .signInWithAppleButtonStyle(.whiteOutline)
        .frame(width: 280, height: 45)
    }
}