Google Assistant TV Command Not appear

Hi,
I am trying to build a TV remote and intergrade it in Google Assistant using Openhab.

The problem is, when I add the below metadata, I can see the item in Google Assistant as a switch.

But if I add Google Assistant tvPower metadata, it does not appear in Google Assistant page.

Any solutions?

From the documentation:

Group as TV with the following optional members: Switch as tvPower , Switch as tvMute , Dimmer as tvVolume , String as tvChannel , String as tvInput , String as tvApplication , Player as tvTransport

Look at the example, which shows that you have to create a group item that serves as the “remote”, with the members of the group serving as the buttons.

Many thanks