divi-product-search.js

<script>
jQuery(document).ready(function($){ // wait for jQuery to load
  // dynamically add the input below the search box that tells the search that the post type to search are products.
  $(".et-search-form").append('<input type="hidden" name="post_type" value="product" />'); 
  // now for each search box from the Divi module
  $(".et_pb_menu__search-form").each(function() { 
  $(this).append('<input type="hidden" name="post_type" value="product" />'); 
  });
  // now for each search box from the Divi theme builder header
  $(".et_pb_searchform").each(function() { 
  $(this).find('div').append('<input type="hidden" name="post_type" value="product" />');
  });
});
</script>