add_action( 'woocommerce_single_product_summary', 'vietmcn_product_sold_count', 11 );
if ( ! functions_exits( 'vietmcn_product_sold_count' ) :
	function vietmcn_product_sold_count() {
		global $product;
		$vietmcn_out = get_post_meta( $product->id, 'total_sales', true );
		echo '' . sprintf( __( 'Số người đã mua: %s', 'woocommerce' ), $vietmcn_out ) . '';
	}
endif;