Issue with Custom Voicemail greeting

I tried adding a WAV file using the path below through the PBX CLI of the main PBX of our multi-tenant instance that I had already saved to Recordings Management. I found the path after reading this forum post. However, I received a “No such command” response. I was hoping to pre-load name greetings for a new client to their voicemail boxes. Is there a way to do this?

/var/spool/asterisk/voicemail/consortium_for_energy_efficiency-voicemail/200/greet.wav