var request = require("request");
var accountSid = "XXXXXXXXX";
var accountToken = "YYYYYYYYY";
var authKey = "ZZZZZZZZZZ";

var encoding = Buffer.from(authKey + ':' + accountToken).toString('base64')

var options = { method: 'PUT',
  url: 'https://api.exotel.com/v2/accounts/'+ accountSid +'/campaigns/6d49fb6fe1ee4abc8b2c4ea5d2f4015a',
  headers: 
   {
     Authorization: 'Basic ' + encoding,
     'Content-Type': 'application/json' 
    },
  body: 
   { campaigns: 
      [ { caller_id: '0XXXXXXXXX1',
          action: 'pause',
          url: 'http://my.exotel.com/<your_sid>/exoml/start_voice/<app_id>' } ] },
  json: true };

request(options, function (error, response, body) {
  if (error) throw new Error(error);

  console.log(body);
  console.log(JSON.stringify(body))
});

<?php
$curl = curl_init();
$accountSid = "XXXXXXXXXX";
$accountToken = "YYYYYYYYYY";
$authKey = "ZZZZZZZZZZ";

$encoding = base64_encode($authKey .":". $accountToken);
curl_setopt_array($curl, array(
  CURLOPT_URL => "https://api.exotel.com/v2/accounts/".$accountSid."/campaigns/6d49fb6fe1ee4abc8b2c4ea5d2f4015a",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => '{
    "campaigns":[{
    "action": "pause",
    "url": "http://my.exotel.com/<your_sid>/exoml/start_voice/<app_id>"}]}',
  CURLOPT_HTTPHEADER => array(
    "Authorization: Basic ".$encoding,
    "Content-Type: application/json"
  ),
));

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

curl_close($curl);

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

import requests, base64, json

accountSid = "XXXXXXXXX"
authToken = "YYYYYYYYY"
authKey = "ZZZZZZZZZZ"

encoding = base64.b64encode(authKey + ":" + authToken)


url = "https://api.exotel.com/v2/accounts/"+accountSid+"/campaigns/6d49fb6fe1ee4abc8b2c4ea5d2f4015a"

payload = json.dumps({ "campaigns": [{ 
          "action": "0XXXXXXXXX1", 
          "url": "http://my.exotel.com/<your_sid>/exoml/start_voice/<app_id>"]
        })
headers = {
    'Content-Type': "application/json",
    'Authorization': "Basic " + encoding
    }

response = requests.request("PUT", url, data=payload, headers=headers)

print(response.text)
print(json.dumps(json.loads(response.text), indent = 4, sort_keys = True))

package main

import (
	b64 "encoding/base64"
	"fmt"
	"io/ioutil"
	"net/http"
	"strings"
)

func main() {
	// Please provide accountSid, authToken from your Exotel account
	accountSid := "XXXXXXXXX"
	authToken := "YYYYYYYY"
	authKey := "ZZZZZZZZZZ"

	// Encoding the accountSid and authToken, used in Authorization header
	encoding := b64.StdEncoding.EncodeToString([]byte(authKey + ":" + authToken))
	url := "https://api.exotel.com/v2/accounts/" + accountSid + "/campaigns/6d49fb6fe1ee4abc8b2c4ea5d2f4015a"

	payload := strings.NewReader(`{ 
    "campaigns": [{ 
      "action": "pause", 
      "url": "http://my.exotel.com/<your_sid>/exoml/start_voice/<app_id>"
      }]
    }`)

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

	req.Header.Add("Content-Type", "application/json")
	req.Header.Add("Authorization", "Basic "+encoding)
	req.Header.Add("cache-control", "no-cache")

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

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

	fmt.Println(res)
	fmt.Println(string(body))

}