For a tenancy in a region updated to use identity domains prior to the creation of the tenancy, users and groups are managed in only Oracle Cloud Infrastructure Identity and Access Management (IAM).
Determine Whether You Use Identity Domains
If you are not sure if your tenancy uses identity domains, see Differences Between Tenancies With and Without Identity Domains.
Documentation for Identity Services
For more information about Oracle Cloud Infrastructure IAM, IDCS, and the documentation that provides the information you need, see Documentation to Use for Cloud Identity in Overview of IAM in the Oracle Cloud Infrastructure documentation.
How Roles Are Assigned in Identity Domains
With identity domains, roles are assigned to Oracle Cloud Infrastructure IAM groups within a domain, as illustrated in the following diagram.