Wiring pixhawk with alernative board

i am having this alternative board wich i would like to keep
it has 1 sbus in port for reciever (wich has power)
3 servo channels (these all have signal + and -)
1 engine out channel. (rc3 has only signal out)

how should i wire the pixhawk as middle man
when i put the sbus reciever into the pixhawk how do i control the rest of the channels

Solved the issue bij connecting the Reciever in SBUS mode to RCIN pixhawk.
SBus out port from pixhawk to sbusin of the alternative board and cut the powercable only connected the ground and signal cable to sbusin.
and set the pixhawk to sbs out mode.