Occasionally you will need to install a single gem with the RubyGems CLI:

gem install my-gem --source https://TOKEN@gem.fury.io/USERNAME/

Or you may want to permanently add your Gemfury account as source:

gem sources -a https://TOKEN@gem.fury.io/USERNAME/

This will append your repository URL to your ~/.gemrc file.

It is important to include a trailing slash in the repository URL, otherwise gem may have trouble connecting to your Gemfury repository.