curl --request GET \
  --url https://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next \
  --header 'Authorization: Basic <encoded-value>'

import requests

url = "https://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next"

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

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

print(response.text)

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

fetch('https://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next', 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.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next",
  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: 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://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next"

	req, _ := http.NewRequest("GET", 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.get("https://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next")
  .header("Authorization", "Basic <encoded-value>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.cloudtalk.io/v1/dialer/campaigns/{campaignId}/contacts/next")

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

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

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

[
  {
    "campaign_contact_id": "5100",
    "contact_id": "88213",
    "category": "fresh",
    "phone_numbers": [
      "+421900123456",
      "+421255512345"
    ],
    "display_name": "Jane Kowalski",
    "timezone": "Europe/Bratislava",
    "callback_notes": null
  }
]

{
  "statusCode": 400,
  "message": "Validation error",
  "error": "Bad Request",
  "correlationId": "YevPQs",
  "subErrors": [
    "incorrect email"
  ]
}

{
  "code": "UNAUTHORIZED",
  "message": "You are not authorized to access this resource."
}

{
  "statusCode": 404,
  "message": "Not Found",
  "error": "Not Found",
  "correlationId": "YevPQs"
}

{
  "statusCode": 429,
  "message": "Too Many Requests",
  "error": "Too Many Requests",
  "correlationId": "YevPQs"
}

{
  "statusCode": 500,
  "message": "Internal Server Error",
  "error": "Internal Server Error",
  "correlationId": "YevPQs"
}