Mobile app users with paging permission can page a known paging group by dialing *84 followed by # and the number of the paging group, then # again.
The user must first enable VoIP calling on the mobile app device. See VoIP Calling.
Paging group setup is reserved for Admins only. So is the IVR setup function. However, Admins can modify all Groups that are set up by all users.