I had submitted a ticket to support and they had said this isn't possible but I got it figured out and wanted to pass it along. We run a central digital signage in our IT dept that displays ipMonitor dashboard. On reboots I wanted it to auto start the page and login. Since the addition of the guest account and button in ipMonitor, you can now call this URL to accomplish this (you must enable guest l: https://servername/login_form.htm?guestlogin
I posted something like this. You will want to remove the / before the ?.