Can I get electricity from the empty position of the forest man fuse box?

You can get electricity from the safe. There are three empty seats in the safe. From top to bottom, the positions of the one-button start switch are on (power supply is on the left), off (power supply is on the right) and Acc (power supply is on the right). It's not too simple to buy a simple small appliance online.

As for wiring, the position of the ceiling can be directly inserted by hand, and you can understand it by pulling the black sealing strip next to the A-pillar. Be careful not to affect the pop-up of the safety air curtain, then go down to the side cover next to the fuse box, and you can reach in and push it out.