curl --request GET \
  --url https://api.jtl-cloud.com/erp/items/{itemId}/customfields \
  --header 'Authorization: Bearer <token>' \
  --header 'x-tenant-id: <x-tenant-id>'

import requests

url = "https://api.jtl-cloud.com/erp/items/{itemId}/customfields"

headers = {
    "x-tenant-id": "<x-tenant-id>",
    "Authorization": "Bearer <token>"
}

response = requests.get(url, headers=headers)

print(response.text)

const options = {
  method: 'GET',
  headers: {'x-tenant-id': '<x-tenant-id>', Authorization: 'Bearer <token>'}
};

fetch('https://api.jtl-cloud.com/erp/items/{itemId}/customfields', 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://api.jtl-cloud.com/erp/items/{itemId}/customfields",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "x-tenant-id: <x-tenant-id>"
  ],
]);

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

curl_close($curl);

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

package main

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

func main() {

	url := "https://api.jtl-cloud.com/erp/items/{itemId}/customfields"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-tenant-id", "<x-tenant-id>")
	req.Header.Add("Authorization", "Bearer <token>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.jtl-cloud.com/erp/items/{itemId}/customfields")
  .header("x-tenant-id", "<x-tenant-id>")
  .header("Authorization", "Bearer <token>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.jtl-cloud.com/erp/items/{itemId}/customfields")

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

request = Net::HTTP::Get.new(url)
request["x-tenant-id"] = '<x-tenant-id>'
request["Authorization"] = 'Bearer <token>'

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

[
  {
    "CustomFieldId": 123,
    "Value": {}
  }
]

{
  "ErrorCode": "<string>",
  "ValidationErrors": {},
  "Errors": {},
  "ErrorMessage": "<string>",
  "Stacktrace": "<string>"
}