Add our WooCommerce Variation SKU meta key to the SearchWP settings

gistfile1.php

<?php

// reference: https://gist.github.com/jchristopher/0cad8418fd9477c57b53
function my_searchwp_custom_field_keys_variation_skus( $keys ) {
  $keys[] = 'my_product_variation_skus';
  
  return $keys;
}
 
add_filter( 'searchwp_custom_field_keys', 'my_searchwp_custom_field_keys_variation_skus', 10, 1 );