<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://forge.laravel.com/api/orgs/{organization}/servers/{server}/sites/{site}/heartbeats/{heartbeat}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => json_encode([
    'name' => 'My Heartbeat',
    'grace_period' => 2,
    'frequency' => 1,
    'custom_frequency' => '* * * * *'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

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

curl_close($curl);

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

{
  "data": {
    "id": "<string>",
    "type": "heartbeats",
    "attributes": {
      "name": "<string>",
      "status": "pending",
      "grace_period": 1,
      "frequency": 1,
      "custom_frequency": "<string>",
      "ping_url": "<string>"
    },
    "links": {
      "self": {
        "href": "<string>",
        "rel": "<string>",
        "describedby": "<string>",
        "title": "<string>",
        "type": "<string>",
        "hreflang": "<string>",
        "meta": {}
      }
    }
  }
}