The most adopted solution in these cases is the Gitlab. You set up a local web server, install Gitlab on it, configure users, initialize repositories, and then upload local repositories to remote Gitlab repositories.
However, the installation of Gitlab is not trivial, which makes many people opt for Github’s corporate plans, where you can add teams and private repositories.
Each of them has their own trade-off. By adopting Gitlab you save on Github plans and ensure that your projects will have maximum privacy (in the case of a well-configured instance). However, the time lost by someone or a team in setting up Gitlab may not pay off after all. Github, on the other hand, involves recurring payments and you’re assured that your repositories will be almost 100% in the air.
Anderson, look for Gitlab. Good luck!
– gmsantos