curl --request POST \
  --url https://api.lemlist.com/api/campaigns/{campaignId}/leads/ \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "email": "support@lemlist.com",
  "firstName": "John",
  "lastName": "Doe",
  "companyName": "lemlist",
  "jobTitle": "Developer",
  "linkedinUrl": "https://www.linkedin.com/in/johndoe",
  "phone": "+33 123456789",
  "timezone": "Europe/Paris",
  "contactOwner": "login_email@lemlist.com",
  "companySize": "50-100",
  "customVariable1": "any value you want"
}
'

import requests

url = "https://api.lemlist.com/api/campaigns/{campaignId}/leads/"

payload = {
    "email": "support@lemlist.com",
    "firstName": "John",
    "lastName": "Doe",
    "companyName": "lemlist",
    "jobTitle": "Developer",
    "linkedinUrl": "https://www.linkedin.com/in/johndoe",
    "phone": "+33 123456789",
    "timezone": "Europe/Paris",
    "contactOwner": "login_email@lemlist.com",
    "companySize": "50-100",
    "customVariable1": "any value you want"
}
headers = {
    "Authorization": "Basic <encoded-value>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Basic <encoded-value>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    email: 'support@lemlist.com',
    firstName: 'John',
    lastName: 'Doe',
    companyName: 'lemlist',
    jobTitle: 'Developer',
    linkedinUrl: 'https://www.linkedin.com/in/johndoe',
    phone: '+33 123456789',
    timezone: 'Europe/Paris',
    contactOwner: 'login_email@lemlist.com',
    companySize: '50-100',
    customVariable1: 'any value you want'
  })
};

fetch('https://api.lemlist.com/api/campaigns/{campaignId}/leads/', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

require 'uri'
require 'net/http'

url = URI("https://api.lemlist.com/api/campaigns/{campaignId}/leads/")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Basic <encoded-value>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"email\": \"support@lemlist.com\",\n  \"firstName\": \"John\",\n  \"lastName\": \"Doe\",\n  \"companyName\": \"lemlist\",\n  \"jobTitle\": \"Developer\",\n  \"linkedinUrl\": \"https://www.linkedin.com/in/johndoe\",\n  \"phone\": \"+33 123456789\",\n  \"timezone\": \"Europe/Paris\",\n  \"contactOwner\": \"login_email@lemlist.com\",\n  \"companySize\": \"50-100\",\n  \"customVariable1\": \"any value you want\"\n}"

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

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.lemlist.com/api/campaigns/{campaignId}/leads/",
  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([
    'email' => 'support@lemlist.com',
    'firstName' => 'John',
    'lastName' => 'Doe',
    'companyName' => 'lemlist',
    'jobTitle' => 'Developer',
    'linkedinUrl' => 'https://www.linkedin.com/in/johndoe',
    'phone' => '+33 123456789',
    'timezone' => 'Europe/Paris',
    'contactOwner' => 'login_email@lemlist.com',
    'companySize' => '50-100',
    'customVariable1' => 'any value you want'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Basic <encoded-value>",
    "Content-Type: application/json"
  ],
]);

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

curl_close($curl);

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