That depends on your hands ;)

Generally it is a split keyboard tilted to the sides (center higher) and going down where your fingertips are (most keyboards have feet at the up side but should have at the lower side).
Also it should have a form that guides finger.

Just place your hands on the table like a lump of flesh and look, remove any felt pressure and how they are ;)

And if that does not help, this one looks quite good ;)
https://shop.keyboard.io/