Cannot find 'Auth' in scopeを直したいです。

Question

前提

ログイン画面を作っています。
環境
MacBook Air
swift storyboard
firebase
cocoa pods

実現したいこと

ViewControllerで発生しているCannot find 'Auth' in scopeのエラーを直したいです。

発生している問題・エラーメッセージ

Cannot find 'Auth' in scope

該当のソースコード

import UIKit
import Firebase

class ViewController: UIViewController {
    
    @IBOutlet weak var registerbuttom: UIButton!
    @IBOutlet weak var emailTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!
    @IBOutlet weak var usernameTextField: UITextField!
    
    @IBAction func renegisterbutton(_ sender: Any) {
        handleAuthToFirebase()
        print("renegisterbuttom")
    }
    private func handleAuthToFirebase() {
        let email = emailTextField.text
        let password = passwordTextField.text
        
        Auth.auth().createUser(withEmail: email, password: password) { (res,err) in
            
        }
        
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        registerbuttom.isEnabled = false
        registerbuttom.layer.cornerRadius = 10
        registerbuttom.backgroundColor = UIColor.rgb(red: 225, green: 221, blue: 187)
        
        emailTextField.delegate = self
        passwordTextField.delegate = self
        usernameTextField.delegate = self
        
        NotificationCenter.default.addObserver(self, selector: #selector(showKeyboard), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(hideKeyboard), name: UIResponder.keyboardWillHideNotification, object: nil)

    }

    @objc func showKeyboard(notification: Notification) {
        let keyboardFrame = (notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue
        
        guard let keyboardMinY = keyboardFrame?.minY else { return }
        let registerButtomMaxY = registerbuttom.frame.maxY
        let deistance = registerButtomMaxY - keyboardMinY + 20
        
        let transform = CGAffineTransform(translationX: 0, y: -deistance)
        
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: [], animations: {
            self.view.transform = transform
        })
        
        //print("keyboardMinY : ", keyboardMinY, "registerButtomMaxY: ", registerButtomMaxY)
    }
    
    @objc func hideKeyboard() {
        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: [], animations: {
            self.view.transform = .identity
        })
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.view.endEditing(true)
    }
}

extension ViewController: UITextFieldDelegate {
    
    func textFieldDidChangeSelection(_ textField: UITextField) {
        let emailIsEmpty = emailTextField.text?.isEmpty ?? true
        let passwordIsEmpty = passwordTextField.text?.isEmpty ?? true
        let usernameIsEmpty = usernameTextField.text?.isEmpty ?? true
        
        if emailIsEmpty || passwordIsEmpty || usernameIsEmpty {
            registerbuttom.isEnabled = false
            registerbuttom.backgroundColor = UIColor.rgb(red: 225, green: 221, blue: 187)
        } else {
            registerbuttom.isEnabled = true
            registerbuttom.backgroundColor = UIColor.rgb(red: 225, green: 141, blue: 0)
        }
        
       
    }
}

エラーが出ている部分

        Auth.auth().createUser(withEmail: email, password: password) { (res,err) in
            
        }

Answer 1

UIKitでFirestoreを使用したことがないのでわかりませんが、

import UIKit
import Firebase
// FirebaseAuth追加
import FirebaseAuth

インポートしてあげれば解決するのではないでしょうか