You need to activate a user for ssh access via Copssh Control Panel.
Your ssh-activated user needs to be enabled for public key authentication (pka). This can be done by clicking Keys button for the selected user in the Control Panel. You can either import a public key of your own (Import button), or let the pka wizard (Add button) create a pka key pair for you.
Create a git repository. It is so simple as to enter the command below from the Bash shell (available from Copssh start menu):
git init --bare /home/youruser/repo-a
You can now access your newly created repository from Git clients by using the url below: