Gitlab for AD authentication users


I need to setup Gitalab for our internal people. I have a setup and git is manageable from command line. Our office members have AD authentication and few people have different ssh pub keys generated on different linux servers.

My question is that how they can access git with ssh key as they have different keys generated which will be not replaced. They are being used in production environment.

They can simply add their pub keys to their profile in gitlab. They can add as many as they want and continue using them.