Fix for Free shipping label in Funnelkit

function custom_shipping_label_based_on_cart_total($output, $method) {
    $cart_total = WC()->cart->cart_contents_total;

    // SUMA ZA BEZPLATNA DOSTAVKA
    $free_shipping_threshold = 200; //На мястото на 200 напишете сумата за безплатна доставка на вашият магазин!

    if ($cart_total >= $free_shipping_threshold) {
        $output = __('Free Shipping', 'woocommerce');
    } else {

        if ($method->cost > 0) {
            $output = wc_price($method->cost);
            if ($method->get_shipping_tax() > 0) {
                $label = wc_prices_include_tax() ? WC()->countries->ex_tax_or_vat() : WC()->countries->inc_tax_or_vat();
                $output .= ' <small class="tax_label">' . $label . '</small>';
            }
        } else {

            $output = '';
        }
    }

    return $output;
}
add_filter('wc_cart_totals_shipping_method_cost', 'custom_shipping_label_based_on_cart_total', 10, 2);