ssh-keygen -t rsa -b 4096 -f ~/.ssh/websupport-ssh -C "toth.janci@gmail.com"

git remote add sshorigin git@gitlab.websupport.sk:linuxinuse/arch-dotfiles.git
git add -f <some-file>
git commit -m "Adding some file: <some-file>"
git push sshorigin master

Please setup ‘'~/.ssh/config’' file

vim ~/.ssh/config

...
# linuxinuse account
Host gitlab.websupport.sk
        HostName gitlab.websupport.sk
        User git
        IdentitiesOnly yes
        IdentityFile ~/.ssh/websupport-ssh
...
:wq!