Oh! If all you want is to know that they've happened then that can actually be done. If you go into Organization > Summary reports, select you appliance network at the top under "Networks(s)", and then scroll WAYYYYY down to the bottom right where you will find the section "Top Security Threats by Signature". There you will find all the IDS/IPS rules that have been triggered, and how many times. You can then set up an auto email of this report to yourself on a reoccurring frequency (daily? weekly?).
So not real time alerting by a long shot, but maybe that would work for you?