Ruby nooby looking for help installing logstash-input-okta plugin

I am having difficulties due to not being very familiar with ruby and the fact that the security dept blocked access to github. I was able to obtain the files locally but when i go to edit the logstash Gemfile the comments indicate that I am not suppose to directly edit this file. Any help would be appreciated, thank you.

I'm working with ver 7.2.1 of Logstash. and Openjdk 11