who is owner for actor for rpc?

hello everyone, I can’t understand the logic of RPC requests in any way, can someone help?
in I have a controller, it has a game manager, and in it an actionmanager, everything is replicated
and in the ui I press the button that in the action manager calls the buy method, and in this method serverBuy is called, which is marked as server and reliable - and the latter method does not work, apparently due to the peculiarities of ownership and rpc