Multiple battery setup

I’m building a large quadcopter. I want to put 2 battery and want to monitor both using QGC. According to px4 it can be set as BAT2*. But when I search inside parameters it did not show. Please help!!!

You can also set the second battery from POWER tab from QGC and connect your second battery sensor output to Power 2 port on your flight controller

Yes it’s showing now but how can I configure it for fuel flow sensor…I need to measure fuel amount from my copter.