I pulled mine down and then started checking the wiring (2021 base LX manual) and did not find a power lead that was switched, just constant and one connected to the interior lights).
I decided to run a wire from the fuse box, up the drivers side door frame, pillar and up to the rear view mirrror area and then down. At least, that was my plan, haven't gotten around to it yet.
(IIRC, you remove the sunglasses tray by squeezing the sides out, then remove two screws, then pull it down in a very "this is going to break on me" fashion. There might be more screws inside the lights, my memory is fuzzy.)
I hope this little bit helps, sorry to be so vague.
If you have the UVO buttons (switched with ignition) it's easy.
I pulled the cover and tapped in the 5v USB converter to the BLK and BRN/RED wires leading tot he mirror.
Stuffed everything back in (surprising amount of room left in the cover) and snapped it back into place.