U=R*I vs. Lightbulb with 40W pulls 40W no matter how high the voltage is

So is this website simply talking trash?

I know it is german, but they have a example calculation for a coffeemaker and they calculate it like this:
P=V*I
Amperage of Coffeemaker with 1000W in 12V
I=1000W/12V=83,3A
Amperage of same Coffeemaker with 230V
I=1000W/230V=4,3A

So this can only be a hypothetical example and is not true in reality?