Not wet, but damp is fine.
Wet feet may affect accuracy. They also can make the scale slippery and not safe to use. Only step on the Wyze Scale with dry—or slightly damp—feet, and when the surface of the glass is not wet. If wet, wipe down the scale and your feet before stepping on.
Note: Wyze Scale is IPX3 rated, which means it can handle light water sprays. It is not waterproof.