In order to access a popup window with the Automation Browser, the “(ShowDialogs)” suffix should be applied at the end of the URL, inside the "Launch New Internet Explorer" action. In this way, we allow such dialogs to pop up. 

For example, the popup could be an authentication window. If the desired URL is http://www.xxxxxxxxx, in the "Initial URL" field the following: http://www.xxxxxxxxx(ShowDialogs) should be written, as shown below.