woocommerce hide shipping method if free is available php

1/**
2 * @snippet       Hide one shipping option in one zone when Free Shipping is available
3 * @how-to        Get CustomizeWoo.com FREE
4 * @author        Rodolfo Melogli
5 * @compatible    WooCommerce 3.6.3
6 * @donate $9     https://businessbloomer.com/bloomer-armada/
7 */
8  
9add_filter( 'woocommerce_package_rates', 'bbloomer_unset_shipping_when_free_is_available_in_zone', 10, 2 );
10   
11function bbloomer_unset_shipping_when_free_is_available_in_zone( $rates, $package ) {
12      
13// Only unset rates if free_shipping is available
14if ( isset( $rates['free_shipping:8'] ) ) {
15     unset( $rates['flat_rate:1'] );
16}     
17     
18return $rates;
19  
20}
21