How to control galaxi watch volume? And android talk.

I'm really not able to find any documentation. I'm just helping sb to repair the watch to the phone. As a side note, it's very slow kinda usable, the phone itself is not that bad, it's an s20.
By the way, what's the problem with whatsapp? We have the actions, and from my 5min testing it seemed more usable than rumours suggest?