In this article , we are going to develop Hello World ! plugin with Redmine. For this tutorial , we have used Ubuntu 20.04 LTS as a base and Redmine 4.1.1 also Ruby version is 2.7 . Note : Before getting started we assume that you have a working Redmine installation. Step 1: Develop Hello World! plugin with redmine plugin generator open terminal and change your current directory to your redmine installation directory i.e. /usr/share/redmine-4.1.1. Use following command, cd /usr/share/redmine-4.1.1/ Now , here we will create plugin using redmine plugin generator script, use following command to generate plugin . export RAILS_ENV="production" above command will set rails environment variable to production and now generator script. bundle exec ruby bin/rails