curl --request POST \
  --url https://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization \
  --header 'Authorization: Basic <encoded-value>'

import requests

url = "https://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization"

headers = {"Authorization": "Basic <encoded-value>"}

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

print(response.text)

const options = {method: 'POST', headers: {Authorization: 'Basic <encoded-value>'}};

fetch('https://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization', 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://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_HTTPHEADER => [
    "Authorization: Basic <encoded-value>"
  ],
]);

$response = curl_exec($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://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization"

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

	req.Header.Add("Authorization", "Basic <encoded-value>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization")
  .header("Authorization", "Basic <encoded-value>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://panel.sendcloud.sc/api/v3/event-subscriptions/connections/{id}/authorization")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Basic <encoded-value>'

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

{
  "data": {
    "authorization_url": "https://www.klaviyo.com/oauth/authorize?client_id=sendcloud&response_type=code&redirect_uri=https%3A%2F%2Fpanel.sendcloud.sc%2Fapi%2Fv3%2Fevent-subscriptions%2Fconnections%2Fauthorization%2Fcallback&state=abc123"
  }
}

{
  "errors": [
    {
      "status": "<string>",
      "code": "unknown_field",
      "detail": "<string>",
      "id": "<string>",
      "links": {
        "about": "<string>"
      },
      "title": "<string>",
      "source": {
        "pointer": "<string>",
        "parameter": "<string>",
        "header": "<string>"
      },
      "meta": {}
    }
  ]
}