Please let me know if this may be a bad place for this, and if so what sub may be recommended instead.

At my work for the woodshop we have a remote that can be carried on a person and pressed in case of an emergency when they are working alone. When pressed a flashing red light right outside the shop near other peoples work stations goes off.

I want to expand the capability and make it so certain people within the plant will receive a phone alert as well.

Can anyone suggest software / hardware that I could use for this? I only need alerts sent to about a dozen or less people (myself and a few managers), and our shop use iPhone SE phones (the ones from like 2016).