I figured out how to add remote account (GitLab EE using personal token). However I am still not able to fetch existing repo or clone one.
The strange thing is that if I select Remote on a new tab, it's showing me all remote repositories based on my GitLab EE credential.
However if I click clone on one of them, it'd say it is not a valid source path/url.
I don't know where else am I supposed to setup credential.