Wheel - How do I get FFB from the wheel

hey guys, i get two different brands of device, wheel is moza, pedals is pxn ,
i can not feel any FFB when both devices are working on my PC , but FFB works when there is only wheel working.
my question is how do i get FFB from the wheel, when both devices are working at the sametime, do I need to configure anything on PC?
please give me some opinions thanks