test.js

<script>
(function($) {
  $(document).on('facetwp-loaded', function() {
    // Change the "SKU" placeholder text (autocomplete facet)
    $('.facetwp-facet-sku .facetwp-autocomplete-update').attr('placeholder', 'My placeholder');

    // Change the "dira" placeholder text (search facet)
    $('.facetwp-facet-dira .facetwp-search').attr('placeholder', 'Another placeholder');
  });
})(jQuery);
</script>