curl --request POST \
  --url https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId} \
  --header 'Authorization: Bearer <token>'

const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}"

headers = {"Authorization": "Bearer <token>"}

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

print(response.text)

using RestSharp;


var options = new RestClientOptions("https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddHeader("Authorization", "Bearer <token>");
var response = await client.PostAsync(request);

Console.WriteLine("{0}", response.Content);

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}",
  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: Bearer <token>"
  ],
]);

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

curl_close($curl);

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

HttpResponse<String> response = Unirest.post("https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}")
  .header("Authorization", "Bearer <token>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'

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

const url = 'https://api.virtuoussoftware.com/api/Contact/{contactId}/Collection/{collectionInstanceId}';
const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

fetch(url, options)
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error(err));

{
  "customCollectionId": -51773297,
  "customCollectionName": "sint",
  "collectionInstanceId": 38041317,
  "fields": [
    {
      "name": "sit tempor in fugiat",
      "value": "sint cupidatat"
    },
    {
      "name": "officia",
      "value": "sint exercitation magna"
    }
  ]
}