How to share a private github repo for a company?

Question

GitHub

There is a company X that has a private repo R .
And company X wants the slaves to work in their private repo R on the right branch.
So that slaves can push they added one user ("general").
But how to do it so that you do not have to authorize the "general" user each time, but use a personal one?
What are the options ? Without the total addition of each developer to the pen?