Woocommerce - hide chargable shipping methods when free shipping is available

functions.php

//
// Hide chargable shipping methods if free shipping is valid
// Thanks to https://flexibleshipping.com/woocommerce-free-shipping-over-amount/
//
function bl_hide_shipping_when_free_is_available( $rates ) {
	$free = array();

	foreach ( $rates as $rate_id => $rate ) {
		if ( 'free_shipping' === $rate->method_id ) {
			$free[ $rate_id ] = $rate;
			break;
		}
	}

	return ! empty( $free ) ? $free : $rates;
}

add_filter( 'woocommerce_package_rates', 'bl_hide_shipping_when_free_is_available', 100 );