As you transition to Flex, vRealize Operations Chargeback is a product edition that is already part of the Core, and you wouldn’t require to report the product separately.
If you deploy vRealize Operations with the intend to use Chargeback functionalities, Usage Meter may still detect the product which could prompt you to enter access credentials. Please make sure not to provide the credentials and so separate vRealize Operations line item will not be generated in the usage reports.
For all other editions such as vRealize Operations Standard/Advanced/Enterprise, please complete registration by providing credentials. If you wish to setup vRealize Operations for Monitoring a subset of VMs and Chargeback for other VMs, please refer to the Usage Meter User Guide on how to meter a subset of VM’s for Operations Manager.