You can give it anything up to 60v or something like that. I just used a spare 24v PSU, but that means it can’t output more than 23v.
I currently own the 6a model but need more and super happy with it, so I have the larger model linked above on order. I haven’t figured out what to power it with yet, I’ll probably just find some cheap PSU on amazon.
They give you data logging, and will even graph consumption on the display live.