Some ebikes can supply 6V or 12V. The second light is 12V only, so ebike only.
Lots of ebikes with OEM mudguards have a hole drilled in them and a channel for routing a light cable straight from the mudguard to the bottom of the seat tube where the motor normally is.
Just checking ... are Supernova's tail lights the same for dynamo and ebike?
This ebay listing seems to suggest this fender tail light is compatabile with both
https://www.ebay.co.uk/itm/256013667602
But on the supernova website it does mention "energy supply via e-bike system"
https://supernova-lights.com/en/products/e3-tail-light-2-universal-fender-mount
It's a slick little unit, altough I can't quite get my head around the angle the cable comes out of the unit i.e. directly into the mudguard / wheel