That was an amazing article. I did used to do this before, but now it doesn’t work for some reason, maybe GitHub improved their responsive website. I skimmed through their HTML code and found an alternative to this solution.
Just go to /fork for that repo. For eg: if the repo is github.com/user/reponame then go to github.com/user/reponame/fork and it will ask for confirmation and you are good to go.