Where should I install the Gem for the Github repository - Jekyll blog?

Question

GitHub

Hello. There is a repository on Github. To enable the pagination plugin, you need to install it:
gem install jekyll-paginate-v2
Installed rubyinstaller-devkit-2.5.5-1-x64
Installed Git and Github Desktop.
Launched CMD from Github Desktop and made a command gem install jekyll-paginate-v2
Is it possible and how to use Gems for GitHub pages?
Thank you.