For my photo, I used the overhead light's power cable as the power source. It is already up there. But that power is always on even if the car is turned off. Might not be good if you don't remove the camera always or doesn't turn off automatically. I was only going to use that power temporarily.
I did run a wire from the fuse box by the foot area up to that hole a few days later. I had to remove the plastic "A pillar" trim. Some people don't remove it and shove a wire behind it. But some cars have air bags behind that pillar trim. Best to remove trim cover first and run the wire.
You can probably use the power from the rear view mirror.