情节提要 （<UIStoryboard： 0x600002c51ec0>） 不包含标识符为“AlphabetController”的视图控制器

问：

 @objc func abcPressed() {
        DispatchQueue.main.async { [weak self] in
            guard let self = self else { return }
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let controller = storyboard.instantiateViewController(withIdentifier: AlphabetController.storyboardIdentifier) as! AlphabetController
            
            controller.modalPresentationStyle = .fullScreen
            self.present(controller, animated: true, completion: nil)
        }
    }

当我按下 abcPressed 时，出现错误“Storyboard （<UIStoryboard： 0x600002c51ec0>） doesn't contain a view controller with identifier 'AlphabetController”

如何通过代码识别AlphabetController？

请帮帮我！谢谢

class AlphabetController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    
    var collectionView: UICollectionView!
    let alphabet = ["A", "Ă", "Â", "B", "C", "D", "Đ", "E", "Ê", "G", "H", "I", "K", "M", "N", "O", "Ô", "Ơ", "P", "Q", "R", "S", "T", "U", "Ư", "V", "X", "Y"]
    var audioPlayer: AVAudioPlayer?
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        }

我试过了

extension AlphabetController {
    static var storyboardIdentifier: String {
        return String(describing: self)
    }