React-hook-form register few states with a button

I want to register to my form a useStates when pressing a button. I mean, that the client won't be must to fill an input to register the form. by pressing a button, my particular useStates will register to the form and the user will go to the next step of the same form.

These are my states and button:

let [designWidth, setDesignWidth] = React.useState<number>();
let [designHeight, setDesignHeight] = React.useState<number>();
let [designX, setDesignX] = React.useState<number>();
let [designY, setDesignY] = React.useState<number>();
let [designRotation, setDesignRotation] = React.useState<number>();
<button type="button" {...register}>Register and continue</button>

Is there a way that I can do it? Thanks!