curl --request POST \
  --url https://vouchers.api.jtl-software.com/v1/clients/connect \
  --header 'Content-Type: application/json' \
  --data '
{
  "pin": "X53HI0"
}
'

import requests

url = "https://vouchers.api.jtl-software.com/v1/clients/connect"

payload = { "pin": "X53HI0" }
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({pin: 'X53HI0'})
};

fetch('https://vouchers.api.jtl-software.com/v1/clients/connect', 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://vouchers.api.jtl-software.com/v1/clients/connect",
  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([
    'pin' => 'X53HI0'
  ]),
  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://vouchers.api.jtl-software.com/v1/clients/connect"

	payload := strings.NewReader("{\n  \"pin\": \"X53HI0\"\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://vouchers.api.jtl-software.com/v1/clients/connect")
  .header("Content-Type", "application/json")
  .body("{\n  \"pin\": \"X53HI0\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://vouchers.api.jtl-software.com/v1/clients/connect")

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  \"pin\": \"X53HI0\"\n}"

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

{
  "id": "da39a3ee5eb28b7392ef5",
  "client_group_id": "cff8784e5eb28b81ca02a",
  "name": "Test-Client",
  "secret": "VrhgrKVDTqjg1GVr3R6Juvx7FfHQK7Psim7ORAXm",
  "scopes": [
    "can_use"
  ],
  "created_at": "2017-07-21T17:32:28+00:00",
  "updated_at": "2017-07-21T17:32:28+00:00",
  "connected_at": "2017-07-21T17:32:28+00:00",
  "type": "pos"
}

"Invalid pin or client was already registered"

{
  "status": 404,
  "code": "VOUCHER.NOT_FOUND",
  "message": "The requested Voucher was not found."
}

{
  "status": 422,
  "code": "VOUCHER.CREATE.UNPROCESSABLE_ENTITY",
  "message": "The given data was invalid.",
  "errors": [
    {
      "code": "VOUCHER.CREATE.CURRENCY.VALID_CURRENCY",
      "property": "currency",
      "rule": "valid_currency",
      "message": "Currency must be a valid currency code"
    }
  ]
}