I've hardwired my dashcam into the wife's ZS EV (this is the 4th car I've hardwired a dashcam to and they're all pretty similar - just a different fuse board layout).
My dashcam requires a 'switched' live and a permanent live (it monitors for 'collisions' and if something were to strike my car - say another car hits mines whilst they are trying to park - my dashcam switches on and records, if it's not already on).
So I've used the fuses for the cigarette lighter socket and one of the rear windows. Just below the fuse board, is a bolt which already has a cable connected to it - this can be used for the negative cable of your dashcam and the positive cable goes into your piggyback fuse holder, as discussed in the earlier posts above.
Looking at the piggyback fuse holder, there are 2 slots. The slot closest to the metal pins of the piggyback fuse holder is for the fuse you remove from the fuse board of your car - in my case, if you hold the piggyback fuse holder horizontally and has its cable going to the right, it's the bottom slot.
The other slot is the fuse which will power your dashcam (or whatever device you're hardwiring).
Hope this helps!
Cheers
Bloggsy