It is explained here:
Taito Type X · argonlefou/DemulShooter Wiki · GitHub
Look for Silent Hill the Arcade explanation to set it up with DemulShooter and Operation Ghost must be done the same way!
Good luck!
Script (put it in the Running Auto Hotkey Script tab) for closing game with ecs button:
; This section closes Operation Ghost when pressing Escape
$Esc::
{
Process, Close, {{{StartupEXE}}}
}