public function post($checkoutSessionId) {
        $order = (new API\WelcartEntries())->getOrder();
        $payload = [
            'chargeAmount' => [
                'amount' => $order['total_full_price'],
                'currencyCode' => usces_crcode('return'),
            ],
        ];
        $headers = ['x-amz-pay-Idempotency-Key' => uniqid()];

        try {
            $client = $this->module->getAmazonClient();
            $result = $client->completeCheckoutSession($checkoutSessionId, $payload, $headers);
            if ($this->module->errors->hasError($result)) {
                return $this->module->errors->getAmzErrorResponse($result, $this);
            }
        } catch (\Exception $e) {
            return $this->module->errors->getErrorResponse(
                GenericErrorStore::AMAZON_PAY_SDK_CLIENT_EXCEPTION,
                [$e->getMessage()]
            );
        }

        return $result;
    }