//**** REQUIRED ****//
        /// biometric class instance
        var biometricAuth = SPAuthentication()
        biometricAuth.delegate = self
        biometricAuth.start()
        
        // MARK:- Authentication delegates
        
    extension SPTouchIDViewController: LocalAuthDelegate {
    func authenticationFinished(string: String) {
        DispatchQueue.main.async {
          self.promtLabel.text = ""
          self.validationPassed()
        }
    }
    func authenticationFinishedWithError(error: String) {
        DispatchQueue.main.async {
          self.promtLabel.text = error
        }
      }
    }