If you are a Freie Universität Berlin member with an FU-Account, you are authenticated through Shiboleth; that means no special registration to Refubium is necessary. You can simply log in on the login page with your FU-Account (ZEDAT) credentials.
Users without a valid FU-Account, i.e., external users and members of Charité – Universitätsmedizin (the latter defined as Freie Universität Berlin members in Berliner Universitätsmedizingesetz, § 4 (2)), have to register when they first log in to Refubium – thereby creating a specific Refubium account.
If you decide to create a Refubium account, you will have to enter a valid e-mail address in the registration process. You will receive an e-mail with a confirmation link that will lead you to the registration form that you need to complete with your user details in order to conclude registration. Immediately thereafter, you will be qualified to submit documents, theses, and research data to Refubium.