Use this method in a separate window ("popup" mode) to render a chat widget that occupies the whole page. Normally, if you use default provided chatWidget.html, you never have to use this method.
This method returns a promise similar to the one returned by startChat.
Most of the options are extracted from the URL, which is formed by the startChat method, if called to create a chat in "popup" mode. However, some options cannot be passed in the URL but must be passed directly. These include: