You can try to use the URL Redirector widget ( https://appstore.home.mendix.com/link/app/113/ ). You can:
- Put it on an empty page. Then you can open this page when you click the button and the widget will navigate to the link entered.
- Place the widget on the same page as your button and use a boolean atribute to see determine whether the widget should be visible. When you click the button, you can switch a boolean attribute, which will show the widget and navigate to the other page.