Problem with Google Assistant add-on

I installed the add-on, configured everything by following the guide. Now how do I change language, play music… and use it like a normal google home?

Do you have a google home or google home mini?
You’ll need one. Or at the very least you’ll need the google assistant app on your phone to send voice commands.

No, I don’t have it. Google assistant add on for Hass.io is a Google home yet

Sorry didn’t realise you were on hass.io. Sorry I can’t help then as I don’t use it.