This happens when your user account doesn't have a valid tenant link — usually when your user was accidentally created from a super-admin context without an agency link.
Solution: ask an admin of your agency to recreate your user via /admin/users from an agency context, or contact support. As soon as the tenant link is correct, your ref link appears immediately.
Super-admins (Senly team) on this page see a platform-wide overview of all affiliates, not their own ref link.