<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Users\Item\OnlineMeetings\CreateOrGet\CreateOrGetPostRequestBody;
use Microsoft\Graph\Beta\Generated\Models\MeetingParticipants;
use Microsoft\Graph\Beta\Generated\Models\MeetingParticipantInfo;
use Microsoft\Graph\Beta\Generated\Models\IdentitySet;
use Microsoft\Graph\Beta\Generated\Models\Identity;
use Microsoft\Graph\Beta\Generated\Models\OnlineMeetingRole;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new CreateOrGetPostRequestBody();
$requestBody->setStartDateTime(new \DateTime('2020-02-06T01:49:21.3524945+00:00'));
$requestBody->setEndDateTime(new \DateTime('2020-02-06T02:19:21.3524945+00:00'));
$requestBody->setSubject('Create a meeting with customId provided');
$requestBody->setExternalId('7eb8263f-d0e0-4149-bb1c-1f0476083c56');
$participants = new MeetingParticipants();
$attendeesMeetingParticipantInfo1 = new MeetingParticipantInfo();
$attendeesMeetingParticipantInfo1Identity = new IdentitySet();
$attendeesMeetingParticipantInfo1IdentityUser = new Identity();
$attendeesMeetingParticipantInfo1IdentityUser->setId('1f35f2e6-9cab-44ad-8d5a-b74c14720000');
$attendeesMeetingParticipantInfo1Identity->setUser($attendeesMeetingParticipantInfo1IdentityUser);
$attendeesMeetingParticipantInfo1->setIdentity($attendeesMeetingParticipantInfo1Identity);
$attendeesMeetingParticipantInfo1->setRole(new OnlineMeetingRole('presenter'));
$attendeesMeetingParticipantInfo1->setUpn('test1@contoso.com');
$attendeesArray []= $attendeesMeetingParticipantInfo1;
$participants->setAttendees($attendeesArray);
$requestBody->setParticipants($participants);
$result = $graphServiceClient->me()->onlineMeetings()->createOrGet()->post($requestBody)->wait();