Register vRA embedded vCO as vCenter Server extension?

Hi all - I have a dev vRA environment that I'd like to leverage the embedded vCO/vRO of in order to expose some workflows from within vCenter.

I've tried the process under "Register Orchestrator as a vCenter Server Extension" in documentation for vRO but not entirely sure what the URL would be considering it's an embedded vCO in vRA.

Any help?

I guess I could install a standalone vRO, register it to vCenter, register vCenter to it, and then still manage the vCenter from the embedded vCO but that gets messy and confusing.

Thanks!