curl --request POST \
  --url https://{merchant_site_domain}/checkout-validate-cart-voucher-url \
  --header 'Content-Type: application/json' \
  --data '
{
  "CartHash": "",
  "CartId": "36048",
  "CartToken": "f8a78edd-7cea-4cb7-835c-57c7f0b13c56",
  "CountryCode": "IL",
  "CurrencyCode": "ILS",
  "Discounts": [],
  "FreeShippingCouponCode": "",
  "IsFreeShipping": false,
  "MerchantGUID": "<MERCHANT_GUID>",
  "Products": [],
  "UserId": null,
  "VoucherCode": "10Perc",
  "VoucherType": 1,
  "WebStoreCode": null,
  "WebStoreInstanceCode": "GlobalEDefaultStoreInstance"
}
'

import requests

url = "https://{merchant_site_domain}/checkout-validate-cart-voucher-url"

payload = {
    "CartHash": "",
    "CartId": "36048",
    "CartToken": "f8a78edd-7cea-4cb7-835c-57c7f0b13c56",
    "CountryCode": "IL",
    "CurrencyCode": "ILS",
    "Discounts": [],
    "FreeShippingCouponCode": "",
    "IsFreeShipping": False,
    "MerchantGUID": "<MERCHANT_GUID>",
    "Products": [],
    "UserId": None,
    "VoucherCode": "10Perc",
    "VoucherType": 1,
    "WebStoreCode": None,
    "WebStoreInstanceCode": "GlobalEDefaultStoreInstance"
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    CartHash: '',
    CartId: '36048',
    CartToken: 'f8a78edd-7cea-4cb7-835c-57c7f0b13c56',
    CountryCode: 'IL',
    CurrencyCode: 'ILS',
    Discounts: [],
    FreeShippingCouponCode: '',
    IsFreeShipping: false,
    MerchantGUID: '<MERCHANT_GUID>',
    Products: [],
    UserId: null,
    VoucherCode: '10Perc',
    VoucherType: 1,
    WebStoreCode: null,
    WebStoreInstanceCode: 'GlobalEDefaultStoreInstance'
  })
};

fetch('https://{merchant_site_domain}/checkout-validate-cart-voucher-url', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://{merchant_site_domain}/checkout-validate-cart-voucher-url",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'CartHash' => '',
    'CartId' => '36048',
    'CartToken' => 'f8a78edd-7cea-4cb7-835c-57c7f0b13c56',
    'CountryCode' => 'IL',
    'CurrencyCode' => 'ILS',
    'Discounts' => [
        
    ],
    'FreeShippingCouponCode' => '',
    'IsFreeShipping' => false,
    'MerchantGUID' => '<MERCHANT_GUID>',
    'Products' => [
        
    ],
    'UserId' => null,
    'VoucherCode' => '10Perc',
    'VoucherType' => 1,
    'WebStoreCode' => null,
    'WebStoreInstanceCode' => 'GlobalEDefaultStoreInstance'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://{merchant_site_domain}/checkout-validate-cart-voucher-url"

	payload := strings.NewReader("{\n  \"CartHash\": \"\",\n  \"CartId\": \"36048\",\n  \"CartToken\": \"f8a78edd-7cea-4cb7-835c-57c7f0b13c56\",\n  \"CountryCode\": \"IL\",\n  \"CurrencyCode\": \"ILS\",\n  \"Discounts\": [],\n  \"FreeShippingCouponCode\": \"\",\n  \"IsFreeShipping\": false,\n  \"MerchantGUID\": \"<MERCHANT_GUID>\",\n  \"Products\": [],\n  \"UserId\": null,\n  \"VoucherCode\": \"10Perc\",\n  \"VoucherType\": 1,\n  \"WebStoreCode\": null,\n  \"WebStoreInstanceCode\": \"GlobalEDefaultStoreInstance\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://{merchant_site_domain}/checkout-validate-cart-voucher-url")
  .header("Content-Type", "application/json")
  .body("{\n  \"CartHash\": \"\",\n  \"CartId\": \"36048\",\n  \"CartToken\": \"f8a78edd-7cea-4cb7-835c-57c7f0b13c56\",\n  \"CountryCode\": \"IL\",\n  \"CurrencyCode\": \"ILS\",\n  \"Discounts\": [],\n  \"FreeShippingCouponCode\": \"\",\n  \"IsFreeShipping\": false,\n  \"MerchantGUID\": \"<MERCHANT_GUID>\",\n  \"Products\": [],\n  \"UserId\": null,\n  \"VoucherCode\": \"10Perc\",\n  \"VoucherType\": 1,\n  \"WebStoreCode\": null,\n  \"WebStoreInstanceCode\": \"GlobalEDefaultStoreInstance\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{merchant_site_domain}/checkout-validate-cart-voucher-url")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"CartHash\": \"\",\n  \"CartId\": \"36048\",\n  \"CartToken\": \"f8a78edd-7cea-4cb7-835c-57c7f0b13c56\",\n  \"CountryCode\": \"IL\",\n  \"CurrencyCode\": \"ILS\",\n  \"Discounts\": [],\n  \"FreeShippingCouponCode\": \"\",\n  \"IsFreeShipping\": false,\n  \"MerchantGUID\": \"<MERCHANT_GUID>\",\n  \"Products\": [],\n  \"UserId\": null,\n  \"VoucherCode\": \"10Perc\",\n  \"VoucherType\": 1,\n  \"WebStoreCode\": null,\n  \"WebStoreInstanceCode\": \"GlobalEDefaultStoreInstance\"\n}"

response = http.request(request)
puts response.read_body

{
  "IsVoucherValid": true,
  "VoucherType": 1,
  "CartToken": "f8a78edd-7cea-4cb7-835c-57c7f0b13c56",
  "VoucherValidationRestriction": [],
  "ValidationFaliureMessage": ""
}