I want to copy a gitlab project to other repository which be completely independent from original project.
For this reason I tried forking original
I would clone the original project in a sandbox on your local machine, create the new project where you want it, set your new gitlab location as the remote and push there.
Assuming old_url and new_url are your old and new URLs:
git clone
cd
git remote add new_remote
git push --all new_remote
Assuming your new repo was empty when you did this, it will now contain all the branches and tags that exist in the original repo, without any connections to it.