Zoom VOIP Intercom

I am the safety director at a small high school.  Last year our IT dept. switched our phone system from a traditional hard wired system to a ZOOM Voip system.  One of the features we lost was the ability to use our phone system as an emergency mass alert system.  With the previous system we were able to dial a number, speak into the phone and that message would be relayed to all phone extensions in the school.   What I am looking to find out is if this can be done on the ZOOM Voip system and if so how.

Thanks for any advise,

Walt Grzyb

Dir. of Safety, Fryeburg Academy