A license gives a member the right to use the organization, including Kubme AI. The number of licenses depends on your plan.
To take it back: Revoke license. The member keeps their account, but can no longer open the organization.
Filter the list with With a license and Without a license to see who has one.
When opening the organization, Kubme shows License required:
Guests (outside people with whom an item was shared, see Sharing and invitations) do not use a member license. They are counted separately, in your plan's Guests quota.
Upgrade to a higher plan or add users to your subscription: Admin Center › Subscription. See also Plans.