Administrator approval is now required for registering new accounts. If you are registering a new account, and are external to the University, please ask the repository owner to contact ServiceLine to request your account be approved. Repository owners must include the newly registered email address, and specific repository in the request for approval. When inviting external users to your project directly, your external user will need to inform you when they have completed registration/sign up. You will then need to contact ServiceLine to create a ticket for your external user to be approved to access the service.
https://www.southampton.ac.uk/ifls/about/our_students/cr1v16.page