ViewController.swift

//1
func setUpSignInAppleButton() {
    authorizationButton.addTarget(self, action: #selector(handleAppleIdRequest), for: .touchUpInside)
    authorizationButton.cornerRadius = 10
}
//2
class ViewController: UIViewController {
    @IBOutlet weak var authorizationButton: ASAuthorizationAppleIDButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setUpSignInAppleButton()
    }
}