Yes you can.You can't but the main charger and charging the main battery won't help. The frunk power button gets it power from the 12V battery.
But you have to put it on a lift.
Then remove the the plastic cover from the bottom of the car.
Then use a tool to reach up behind the bumper and hook the cable that unlatches the frunk hood.
Then pull on that cable to pop the hood.
Watch the first Rich Rebuilds video. They go through the process.
(There is more than a little bit of sarcasm in this response. But its kinda accurate)