Why can't I find the standard Employee role in the Security tab of Agent Team Settings?

The standard Employee role isn't available in the Security tab because it's a predefined role and can't be modified to add new privileges or roles. Although permission groups can be enabled for predefined roles, you can't edit those roles to add additional privileges.

If you see an Employee-like role available in the Security tab, it's typically a custom role created by copying the predefined Employee role. Predefined roles generally have names that begin with the ORA_ prefix.