After migrating Aria Automation 8.x to VCF Automation 9.x it is not possible to integrate the Operations plugin in VCF Automation 9.x UI using a VCF SSO account.
With Aria Automation 8.x the plugin is configured using an @vidmAuthSource account but VCF 9 uses VIDB not VIDM so using a service account in the plugin will fail with an error similar to:
Failed to validate credentials: Failed to connect to Aria Operations.
VCF SSO accounts are not currently supported by the VCF Operations integration in VCF Automation 9.x
Create a local user account assigning it an administrator role in VCF Operations and use this to configure the plugin in VCF Automation.