As requested. Usually you can accomplish what you need by setting whatever IPS application you like as the default under the Applications menu in the ACP but apparently there are still instances where this may not accomplish what is needed.
This is nothing fancy - you must enter the complete URL in settings. Be sure not to copy/paste the URL from your browser address bar that includes stuff like CSRF= and so on. Keep it simple and you'll be fine.
Tested on 4.3.6, probably fine on all of the 4.3 versions, and likely on 4.2 as well (but that is, and will remain, untested by me).
Confirmed working on 4.4