If it’s Google TV it probably appears as a Chromecast. There isn’t a power Channel though so you can’t directly control the TV power from OH.
I’ve moved to Google TV dongles from Roku and I use a routine in Google Home to turn off the TV at a fixed time which is sufficient for my purposes. If you need more, Tasker or OrangeAssist - Google Assistant Integration would probably be required, until such point that Google Routines support being triggered based on device events.