how to get value of checkbox from react-hook-form?

I am trying to deliver the value of the checkbox using react-hook-form.

I am delivering the register function of react-hook-form to the props of the component.

But here's a problem.

<CheckboxInput
  type="checkbox"
  id={id}
  value="BAD"
  checked={isChecked[1]}
  onChange={handleCheckbox}
  {...register}
/>

If I deliver the props in the above order, the value value of the checkbox is well shown through the watch function of react-hook-form, but the check mark in the checkbox is not appear.

But,

<CheckboxInput
  {...register}
  type="checkbox"
  id={id}
  value="BAD"
  checked={isChecked[1]}
  onChange={handleCheckbox}
/>

If I pass the props in the above order, the check mark in the checkbox appears well, but if I check the value of the checkbox through the watch function in the react-hook-form, only the value 'false' appears.

How can I make sure that the check marks on the checkbox come out well and the exact value comes out?