The windings could be different in wirethickness and turns per loop, but using the same armature/rotor.

Now the simple math. A 36V 800W nominal motor will draw around 25A when operating at good efficiency. Providing the same motor with 24V , it will become a 400W motor for the same efficiency.

But this could be an option.
https://www.aliexpress.com/item/24V3...4-d73b1595e964