Read current volume on Google Nest Mini

I want to query a Google Nest Mini on my home network and get it's current volume.

There are a number of other volume settings (alarm, timers, nightmode), which are easy to query, but not the basic bog standard volume.

Any ideas?

REASON
I am sending messages to it via Google text to speech, turning the volume up high to ensure the message is heard. I want to reset it to the original volume when the message is finished.

Ta!