git server

Just put a bare repository on the server you have access to, rest will be taken care by git.

Assuming the SSH server is already enabled,

1. create a git user that will manage remote repositories

$ sudo useradd -r -m -U -d /home/git -s /bin/bash git

Resources

https://git-scm.com/book/en/v2/Git-on-the-Server-Setting-Up-the-Server

https://www.howtogeek.com/devops/how-to-set-up-a-private-git-server/