Sending an SMS with your code infinite loading screen Account kit IOS

Question

I'm using Account kit for Login using Phone number.

let accountKit = AKFAccountKit(responseType: AKFResponseType.accessToken)
var pendingLoginViewController: UIViewController?

override func viewDidLoad() {
    super.viewDidLoad()
    pendingLoginViewController = accountKit.viewControllerForLoginResume()
}
@IBAction func loginWithEmail(sender: AnyObject) {
    let viewController = accountKit.viewControllerForPhoneLogin(with: nil, state: nil) as! AKFViewController
    viewController.enableSendToFacebook = true
    viewController.enableGetACall = true
    viewController.delegate = self
    present(viewController as! UIViewController, animated: true, completion: nil)
}
private func generateState() -> String {
    let uuid = NSUUID().uuidString.lowercased()
    return uuid
}

Got SMS form Account kit but app infinite loading "Sending an SMS with your code" it should be go next screen for enter login code.

Thanks in Advance.