curl --request POST \
  --url https://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "variable": {
    "in": "<string>",
    "value": "<unknown>",
    "defaultValue": "<unknown>",
    "key": "<string>",
    "description": "<string>",
    "required": true,
    "reusable": true,
    "isEnv": true,
    "isSystem": true,
    "isGlobal": true
  }
}
'

import requests

url = "https://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables"

payload = { "variable": {
        "in": "<string>",
        "value": "<unknown>",
        "defaultValue": "<unknown>",
        "key": "<string>",
        "description": "<string>",
        "required": True,
        "reusable": True,
        "isEnv": True,
        "isSystem": True,
        "isGlobal": True
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    variable: {
      in: '<string>',
      value: '<unknown>',
      defaultValue: '<unknown>',
      key: '<string>',
      description: '<string>',
      required: true,
      reusable: true,
      isEnv: true,
      isSystem: true,
      isGlobal: true
    }
  })
};

fetch('https://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables', 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://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables",
  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([
    'variable' => [
        'in' => '<string>',
        'value' => '<unknown>',
        'defaultValue' => '<unknown>',
        'key' => '<string>',
        'description' => '<string>',
        'required' => true,
        'reusable' => true,
        'isEnv' => true,
        'isSystem' => true,
        'isGlobal' => true
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "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://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables"

	payload := strings.NewReader("{\n  \"variable\": {\n    \"in\": \"<string>\",\n    \"value\": \"<unknown>\",\n    \"defaultValue\": \"<unknown>\",\n    \"key\": \"<string>\",\n    \"description\": \"<string>\",\n    \"required\": true,\n    \"reusable\": true,\n    \"isEnv\": true,\n    \"isSystem\": true,\n    \"isGlobal\": true\n  }\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"variable\": {\n    \"in\": \"<string>\",\n    \"value\": \"<unknown>\",\n    \"defaultValue\": \"<unknown>\",\n    \"key\": \"<string>\",\n    \"description\": \"<string>\",\n    \"required\": true,\n    \"reusable\": true,\n    \"isEnv\": true,\n    \"isSystem\": true,\n    \"isGlobal\": true\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://eu-gcp-api.vg-stuff.com/v3/agents/{agentId}/variables")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"variable\": {\n    \"in\": \"<string>\",\n    \"value\": \"<unknown>\",\n    \"defaultValue\": \"<unknown>\",\n    \"key\": \"<string>\",\n    \"description\": \"<string>\",\n    \"required\": true,\n    \"reusable\": true,\n    \"isEnv\": true,\n    \"isSystem\": true,\n    \"isGlobal\": true\n  }\n}"

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

{
  "success": true,
  "message": "<string>",
  "data": {
    "id": "<string>",
    "in": "<string>",
    "value": "<unknown>",
    "defaultValue": "<unknown>",
    "key": "<string>",
    "description": "<string>",
    "required": true,
    "reusable": true,
    "isEnv": true,
    "isSystem": true,
    "isGlobal": true,
    "agentId": "<string>",
    "userId": "<string>"
  }
}

{
  "message": "<string>",
  "code": "<string>",
  "issues": [
    {
      "message": "<string>"
    }
  ]
}