Reading power level in QGroundControl

Hi everyone!
I’m new to QGroundControl. I’d really appreciate if someone could help me with this. I want to use QGroundControl as the ground station to a Baby Shark airplane from foxtech. This plane has 2 sets of batteries. In Mission Planner I can read the values of the batteries like this

monitor monitor2

In QgroundControl I managed to read one of them, but not the other because the option “4: The Cube or Pixhawk” is not available. The read voltage value is always -1 in the other cases.

Does anyone know how can I get the voltage value of this battery in QGroundControl?
I suppose it should be straightforward. It’s a pixhawk 2.1 (aka Cube). It has 2 power ports.

Thanks in advance