How to stop UE4 game remotely using PixelStreaming?

Hello.
I am trying to start and stop ue4 game using winapi CreateProcess, and kill this process using id which i recieved from CreateProcess. But it doesent stop launched game. I found that process which I launch from winapi creates real game process, but I don’t know its id, so I can’t kill the game. How to get real game process id or stop launched game remotely? Thanks