protected static function getCheckoutBody(CheckoutInterface $checkout): array
    {
        return [
            "checkout_reference" => $checkout->getReference(),
            "amount" => $checkout->getAmount(),
            "currency" => $checkout->getCurrency(),
            "fee_amount" => $checkout->getFeeAmount(),
            "pay_to_email" => $checkout->getPayToEmail(),
            "pay_from_email" => $checkout->getPayFromEmail(),
            "description" => $checkout->getDescription(),
            "return_url" => $checkout->getRedirectUrl(),
        ];
    }