WooCommerce extra fee for cash on delivery cod payment

woo_shipping_functions.php

<?php

// A fee of 5 USD is charged for payment processing by the courier.
add_action( 'woocommerce_cart_calculate_fees', function() {
	$cod_fee = 4.202; // no VAT value
    $chosen_gateway = WC()->session->get( 'chosen_payment_method' );

    if ( $chosen_gateway == 'cod' ) { // 'cod' stands for Cash on Delivery
    	$chosen_shipping_methods = wc_get_chosen_shipping_method_ids();

    	if ( !in_array('local_pickup', $chosen_shipping_methods) ) {    		
    		WC()->cart->add_fee( __('Cash Payment processing fee, online card payment is free.', 'woocommerce'), $cod_fee, true, '' );
    	}
    }
} );