WooCommerce - Add Custom Fee

add_action('woocommerce_cart_calculate_fees', 'dnd_add_custom_fees', 999, 1);

function dnd_add_custom_fees($cart) {
    if (is_admin() || defined('DOING_AJAX')) {
        return;
    }

    $label = get_option('drag_n_drop_cart_fee_label', 'Custom Fee');
    $amount = 0;

    // Debug logging to check if this function is triggered
    error_log('Running dnd_add_custom_fees');

    $file_uploads = wp_list_pluck($cart->get_cart_contents(), 'dnd-wc-file-upload');

    if ($file_uploads && is_array($file_uploads)) {
        foreach ($file_uploads as $files) {
            if ($files && is_array($files) && count($files) > 0) {
                $amount += 8.85;
            }
        }
    }

    if ($amount > 0) {
        foreach ($cart->get_fees() as $key => $fee) {
            if ($fee->name === $label) {
                unset($cart->get_fees()[$key]);
            }
        }

        // Debug logging to confirm the fee amount
        error_log("Adding fee of amount: $amount");

        $cart->add_fee($label, $amount);
    }
}