I have a packaged install of Openproject on a Debian 9 server, and I'm trying to install a plugin that one of our volunteers wrote for us. 

I've created a Gemfile.custom in /etc/openproject, with the GitHub link, I also ran chown to give ownership to the openproject user. 

What I am struggling with is what directory do I need to be in to run bundle install? or any of other Rails commands?