примерно так
private var subscribeButton: UIButton = {
let button = UIButton()
return button
}()
required override public init(frame: CGRect) {
super.init(frame: .zero)
setup()
}
func setup() {
self.contentView.addSubview(subscribeButton)
self.subscribeButton.frame = CGRect(origin: CGPoint(x: 200,y :60), size: CGSize(width: 100, height: 24))
let cellHeight: CGFloat = 44.0
self.subscribeButton.center = CGPoint(x: bounds.width / (4/3), y: cellHeight / 2.0)
self.subscribeButton.addTarget(self, action: #selector(subscribeButtonTapped(_:)), for: .touchUpInside)
}