How to show buttons horizontally? about pmalertcontroller HOT 5 CLOSED

extension PMAlertController {
    static func initWithTextFieldValidation(title: String,
                                            description: String,
                                            textField: UITextField,
                                            confirmButtonTitle: String,
                                            cancelButtonTitle: String,
                                            confirmButtonAction: ((PMAlertController) -> Void)? = nil,
                                            cancelButtonAction: ((PMAlertController) -> Void)? = nil) -> PMAlertController {
        
        // Init the alert
        let passwordAlert = PMAlertController(title: title, description: description, image: nil, style: .alert)
        passwordAlert.gravityDismissAnimation = false
        
        // Create the first fieldStack with the textField and set some insets on side
        let fieldStack = UIStackView(arrangedSubviews: [textField])
        fieldStack.layoutMargins = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
        
        
        // Init actions
        let cancelAction = PMAlertAction(title: cancelButtonTitle, style: .cancel, action: { () -> Void in
            if let action = cancelButtonAction {
                action(passwordAlert)
            } else {
                passwordAlert.dismiss(animated: true, completion: nil)
            }
        })
        let confirmAction = PMAlertAction(title: confirmButtonTitle, style: .default, action: { () in
            confirmButtonAction?(passwordAlert)
        })
        
        // Create second Stack with actions and set his axis to horizontal
        let buttonsStack = UIStackView(arrangedSubviews: [cancelAction, confirmAction])
        buttonsStack.axis = .horizontal
        
        // Add constraint to be sure two buttons have the same width
        buttonsStack.addConstraint(NSLayoutConstraint(item: cancelAction, attribute: .width, relatedBy: .equal, toItem: confirmAction, attribute: .width, multiplier: 1, constant: 0))
        
        // set the alert's StackView axis to vertical and add stacks
        passwordAlert.alertActionStackView.axis = .vertical
        passwordAlert.alertActionStackView.addArrangedSubview(fieldStack)
        passwordAlert.alertActionStackView.addArrangedSubview(buttonsStack)
        
        passwordAlert.alertActionStackViewHeightConstraint.constant = 62 * CGFloat(passwordAlert.alertActionStackView.arrangedSubviews.count)
        
        return passwordAlert
    }
}

let passwordField = UITextField()
        passwordField.font = UIFont.preferredFont(forTextStyle: .body)
        passwordField.isSecureTextEntry = true
        passwordField.textColor = UIColor.bodyGray
        passwordField.placeholder = "Mot de passe"
        passwordField.textAlignment = .center

        let fieldAlert = PMAlertController.initWithTextFieldValidation(title: "Connexion", description: "Entrez votre mot de passe", textField: passwordField, confirmButtonTitle: "Confirmer", cancelButtonTitle: "Annuler",
            confirmButtonAction: { alert in
                //TODO CONFIRM BUTTON
            },
            cancelButtonAction: { alert in
                alert.dismiss(animated: true, completion: nil)
            })

        self.present(fieldAlert, animated: true, completion: nil)