WWQ – Allow quoting out-of-stock products

  add_action( 'woocommerce_single_product_summary', 'wwq_show_quote_button_for_out_of_stock',

   31 );

  function wwq_show_quote_button_for_out_of_stock() {

      global $product;

      if ( ! $product instanceof WC_Product || $product->is_in_stock() ) {

          return;

      }

      if ( ! class_exists( 'WholesaleQuotes\Classes\Frontend\Buttons' ) ) {

          return;

      }

  \WholesaleQuotes\Classes\Frontend\Buttons::instance()->show_quote_button_on_product_page();

  }