The documentation links I provided describe how to get M0065 board running in PX4 as a standard actuator that supports 8 PWM outputs.
If you are familiar with PX4, GCS, Actuators, then look through those documentation pages and follow the setup.
However, i don't have the full information about your hardware, so i don't know if you need some customizations:
are you using voxl2 on a flying drone? if so, are you using a modalai ESC or another ESC? Are you planning to use M0065 board to generate pwm output for your ESC (if you are using a standard ESC that accepts PWM as control input) do you need to use PX4 for your application? the reason why I ask is that you can use M0065 pwm outputs without PX4 if you don't need PX4 at all.Alex