This is the PHP-API for https://callab.me. You can get your API credentials from the settings menu.
<?php
require __DIR__ . '/src/CallabClient.php';
$api_key = "68481fb0-a98e-11ea-b627-8b2a92262801";
$secret_key = "8f0a9c7228e7893ef0f7d9706dce499c34501714";
$base_url = "https://app.callab.me";
// 1. Create instance of Client with credentials
$client = new CallabClient($base_url, $api_key, $secret_key);
// 2. Schedule meeting
$response = $client->scheduleMeeting(
'30.04.2021 13:30:00',
'30.04.2021 13:55:00',
'My meeting with somebody',
'Europe/Berlin'
);
var_dump($response);