How to change output label to placeholder in woocomerce?

Question

WordPress

function truemisha_fio_field( $fields ) {
 
  $fields[ 'billing' ][ 'billing_first_name' ][ 'placeholder' ] = $fields[ 'billing' ][ 'billing_first_name' ][ 'label' ];
 
  return $fields;
 
}

I can change one field at a time, but is it possible to do everything at once somehow?