Manual control in use of MAVLINK RC override

I want to use the manual control without RC but in use of MAVLINK_RC_CHANNELS_OVERRIDE message. Because my drone should fly some KM. So, RC receiver is not working.
So, use the long range datalink and use the telemetry message with MAVLINK_RC_CHANNELS_OVERRIDE message. But in simulation, PX4 can not armed because no rc input.
Is that impossible?