/**
     * @param $amount
     * @return string
     */
    public function getGiftCardPayload($amount, $requestId, $creationId = null)
    {
        $amount = trim($amount);

        $payload = [
           "creationRequestId" => $this->_config->getPartner() . "_" . time(),
            'partnerId' => $this->_config->getPartner(),
            'value' =>
                [
                    'currencyCode' => $this->_config->getCurrency(),
                    'amount' => (float)$amount
                ]
        ];
        return json_encode($payload);
    }