Only a release manager can enable a source control access. With this privilege a release manager can be selecting the GitLab type and entering the gitlab server name. You can supply multiple server names and then use the gitlab personal access token and assign it to the source control server.
By enabling access source control, you can add an endpoint for Source Control. For information on adding source control, see Add a Source Control Server Endpoint. Release manager can add a source control server. But any developer logged-in to LCM will have to associate their token to the server to access the Source control server