When trying to activate license and vSphere Client plug-in management for a particular vCenter account in VCF Operations, following documentation: Configuring a vCenter Account in VCF Operations
Manage Integration
The vCenter credentials you use must have the Global.Licenses privilege assigned and be
a member of the LicenseService.Administrators Single Sign-On group. Go to the vSphere
Client to configure them and try again.
VCF Operations 9.x
The vCenter credential is not a member of the LicenseService.Administrators Single Sign-On group.
To verify that the vCenter credentials that have sufficient privileges to connect and collect data, see Privileges Required for Configuring a vCenterAccount.