Redmine

We have recently installed WBS(https://www.easyredmine.com/redmine-wbs-plugin#features) plugin in redmine:passenger image. Despite that the plugins appear under Administration -> Plugins we are not able to see an addition of new tab on project portlet.

Following are the details:

proadmin@localhost:/usr/src/redmine$ RAILS_ENV=production bin/about
W, [2022-01-04T15:44:15.217169 #393]  WARN -- : Creating scope :system. Overwriting existing method Enumeration.system.
W, [2022-01-04T15:44:15.479267 #393]  WARN -- : Creating scope :sorted. Overwriting existing method Group.sorted.
W, [2022-01-04T15:44:15.497440 #393]  WARN -- : Creating scope :sorted. Overwriting existing method User.sorted.

sh: 1: cvs: not found
Environment:
  Redmine version                4.2.3.stable
  Ruby version                   2.7.5-p203 (2021-11-24) [x86_64-linux]
  Rails version                  5.2.6
  Environment                    production
  Database adapter               PostgreSQL
  Mailer queue                   ActiveJob::QueueAdapters::AsyncAdapter
  Mailer delivery                smtp
SCM:
  Subversion                     1.14.1
  Mercurial                      5.6.1
  Bazaar                         3.1.0
  Git                            2.30.2
  Filesystem                     
Redmine plugins:
  easy_mindmup                   1.0
  easy_wbs                       1.5

We are new to Redmine and would appreciate any guidance or help in this regard.