Contacts : Validation cancel

<?php
$env      = "live"; // live or test
$api_key  = "XXXXXXXX-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
$api_url  = "/v2/contacts/ABCD-0001/validate/cancel";
$api_host = $env === "live" ? "https://api.mijndomeinreseller.nl" : "https://api-test.mijndomeinreseller.nl";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api_host . $api_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt( $ch, CURLOPT_POSTFIELDS, "" );
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Authorization: Bearer $api_key"));
$output = curl_exec($ch);

if(curl_getinfo($ch, CURLINFO_HTTP_CODE) === 204) {
  echo "Contact validation successfully canceled";
}

curl_close($ch);