How to use Google Voice Commands to turn down volume on Chromecast with GTV

Configuration
1

I tried going the routine in the google home app route, but because of the way I am using the chromecast with GTV, does not seem to be working.

I have two issues here:

  1. How can I create a custom command like “Hey google, turn up volume on Pool radio”, and it will call something in Home Assistant.
  2. How do I set up HA to adjust the volume up or down by a specific number?

I have Google Assistant already integrated. I have automation that SETS the volume on my chromecast. This is working.

What I want to do is this:

When I say, “Hey google, turn up pool radio”, it then calls to HA, and HA will adjust the volume.
I can’t get either of these to work.

I dont know how to get the voice commands to call HA, and I keep getting an error when creating a script to adjust volume up.

I am VERY new at this, would anyone be able to walk me through this?

2

quick bump as i am still looking for a solution here or if it is even possible.