Helper/EventIdGenerator.php

<?php
/**
 * Copyright (c) Meta Platforms, Inc. and affiliates. All Rights Reserved
 */

namespace Facebook\BusinessExtension\Helper;

class EventIdGenerator
{
    /**
     * @return string A 36 character string containing dashes.
     */
    public static function guidv4()
    {
        $data = openssl_random_pseudo_bytes(16);

        $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // set version to 0100
        $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // set bits 6-7 to 10

        return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
    }
}