UILabel未显示在视图中

我刚刚开始学习如何在不使用故事板的情况下编程,所以请把我当作初学者。。。即使我的图像出现在屏幕上,标签也没有……我有点困惑为什么会这样,我很感激你的帮助。再说一次,我是个初学者,不介意这是一个愚蠢的错误!!!

import UIKit

class LocationRequestController : UIViewController
{
    let imageView: UIImageView =
    {
        let iconImageView = UIImageView()
        iconImageView.contentMode = .scaleAspectFit
        iconImageView.image = UIImage(named: "blue-pin")
        return iconImageView
    }()

    let allowLocationLabel : UILabel =
    {
        let label = UILabel()
        let attributedText = NSMutableAttributedString(string: "Allow Location\n", attributes: [NSAttributedString.Key.font : UIFont.boldSystemFont(ofSize: 24)])
        attributedText.append(NSAttributedString(string: "Please enable location services For The Map To Work!", attributes: [NSAttributedString.Key.font : UIFont.systemFont(ofSize: 16)]))

        label.numberOfLines = 0
        label.textAlignment = .center
        label.attributedText = attributedText

        return label
    }()
    override func viewDidLoad()
    {
        super.viewDidLoad()
        configureViewAppearance()
    }

    func configureViewAppearance()
    {
        view.backgroundColor = .white

        view.addSubview(imageView)
        imageView.anchor(top: view.topAnchor, left: nil, bottom: nil, right: nil, paddingTop: 140, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: 200, height: 200)
        imageView.centerX(inView: view)

        view.addSubview(allowLocationLabel)
        allowLocationLabel.anchor(top: imageView.bottomAnchor, left: view.leftAnchor, bottom: nil, right: view.rightAnchor, paddingTop: 32, paddingLeft: 32, paddingBottom: 0, paddingRight: 32, width: 0, height: 0)
        allowLocationLabel.centerX(inView: view)
    }
}

再次感谢!