In the vSphere Client, navigating to Administration > Single Sign On > Configuration reveals that the Identity Sources tab is missing.
Only Users and Groups and OpenID Connect are visible. While identity sources may be functionally embedded, they are not listed in the UI.
This is associated with a failure in the Certificate Management service, specifically reporting: service not found com.vmware.vcenter.certificate_management.vcenter.signing_certificate
vCenter 8.x
Missing or unregistered lookup service endpoints and corrupted service registrations prevent the SSO configuration sub-components from initializing in the UI.
Download the latest version of the lsdoctor tool to the affected vCenter Server Appliance.
Connect to the vCenter Server via SSH as root.
Run the tool to rebuild the service registrations and select option 2 - 'Replace all services with new services'
python lsdoctor.py -rRestart all vCenter services to finalize the registration updates: service-control --stop --all && service-control --start --all