Method 1:
Go to http://127.0.0.1/admin/info
, it will be something like this:
Method 2:
view doc/CHANGELOG
On the top, it will be something like this:
== Redmine changelog
Redmine - project management software
Copyright (C) 2006-2021 Jean-Philippe Lang
https://www.redmine.org/
== 2021-03-21 v4.1.2
...
Method 3:
view lib/redmine/version.rb
On the top, it will be something like this:
...
module Redmine
# @private
module VERSION
MAJOR = 4
MINOR = 1
TINY = 2