WooCommerce add weight unit after price filter

woocommerce_price_with_weight.php

<?php 
/**================WooCommerce weight unit after price===================**/
add_filter( 'woocommerce_price_html', 'woocommerce_custom_sales_price', 10, 2 );
add_filter( 'woocommerce_sale_price_html', 'woocommerce_custom_sales_price', 10, 2 );
function woocommerce_custom_sales_price( $price, $product ) {
	return sprintf( __( '%s/kg', 'woocommerce' ), $price );
}