A device transmits an acquisition request for first authorization information indicating that a user's authority to create a tenant-dedicated client is delegated to a vendor client on the basis of first authentication information provided from an authorization server in response to the registration of the vendor client. The device registers the tenant-dedicated client in the authorization server on the basis of the first authorization information, and transmits an acquisition request for second authorization information indicating that the user's authority in a service of a resource server is delegated to the tenant-dedicated client on the basis of second authentication information provided from the authorization server in response to the registration of the tenant-dedicated client. Then the device uses the service of the resource server on the basis of the second authorization information.