Licenses are based on the maximum number of workers able to log in at the same time (i.e. seats). The software can be deployed on independent servers, or as a fully-managed, cloud-based service.
If you purchased a Cerb license you can enter it here to increase your seats. Without a license, Cerb operates in evaluation mode with a single seat but no other restrictions.
If you have a Cerb Cloud subscription then you won’t see this section.