Redmine, how to enable notification for observers?

Question

Redmine

Colleagues, as it turns on, somehow it’s not logical to be honest.
There is a plugin, but it is for version 2.x

Environment:
  Redmine version                3.2.0.stable
  Ruby version                   2.0.0-p598 (2014-11-13) [x86_64-linux]
  Rails version                  4.2.5
  Environment                    production

Answer 1

As far as I know, there is no such thing in redmine. Under this you need to write a plugin.