Discount per shipping method in woocommerce

Discount per shipping method.php

function apply_shipping_based_discounts() {
    $chosen_shipping_methods = WC()->session->get('chosen_shipping_methods');
    $chosen_shipping_method = $chosen_shipping_methods[0];
    $discount = 0;

    if ($chosen_shipping_method === 'free_shipping') {
        $discount = 10; // Discount for free shipping
    } elseif ($chosen_shipping_method === 'flat_rate') {
        $discount = 5; // Discount for flat rate
    } elseif ($chosen_shipping_method === 'local_pickup') {
        $discount = 3; // Discount for local pickup
    }

    if ($discount > 0) {
        WC()->cart->add_fee(__('Shipping Discount', 'woocommerce'), -$discount);
    }
}
add_action('woocommerce_cart_calculate_fees', 'apply_shipping_based_discounts');