Redmine

I just installed Redmine today, so I'm very new to all these features.

I've been able to clone a Github repo, and display it into my Redmine installation. That's great.

But I would like to know if it is possible to use it as an actual Git repo, and not just a Github mirror.
Just to be clear, I would like to push my commits to my Redmine installation and not depend to Github at all.

Is it possible, or is Redmine just a Git "view" ?

PS: Sorry for my english, I hope I've been understandable.