Servo Output Raw Did Not Detect Actuator Control Message

Hi all,

I am using an existing Reaper_500 airframe as the initialisation file within QGC. I was able to publish actuator control message through to mavros node. The group_mix number is set as 0. Screenshot%20from%202019-10-10%2013-07-20
I was able to load a passthrough mixer within QGC using the mavlink console with the following code:
mixer load /dev/pwm_output0 /etc/mixers/FMU_pass.mix
which is supposed to map my actuator control input into PWM signal and be monitored by the servo output raw analyzer within QGC. Though after loading the mixer, I can see the first 4 servo channels displayed a change. However when I published my control messages, the numbers did not change on the screen.
QGC
Can someone point me in the right direction? How can I map the actuator control messages to display in servo out raw?

I found the reason for this is because I didn’t set the PX4 to offboard. The servo output raw can only observe actuator control commands in offboard control mode.