In the hardware setup there is the following:
Power module does not provide power to servos. To provide power to servos connect BEC to the servo rail. BEC would also serve as back-up power supply to Navio2.
I've got a DYS D800 quad: https://www.unmannedtechshop.co.uk/dys-d800-x4-professional-multi-rotor-package-for-aerial-photography-and-heavy-lift-pnf/
I've connected 1 ESC to the Navio2 (channel 1) with all the 3 wires. There is a servo on the channel 7. The issue is, that servo is not doing anything, only if I connect it directly to the X8R receiver's channel 7.
It turned out that: DYS HV40A ESC seems to be OPTO, so it does not have built-in BEC.
What else do I need more?