<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Users\Item\Events\Item\Forward\ForwardPostRequestBody;
use Microsoft\Graph\Generated\Models\Recipient;
use Microsoft\Graph\Generated\Models\EmailAddress;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new ForwardPostRequestBody();
$toRecipientsRecipient1 = new Recipient();
$toRecipientsRecipient1EmailAddress = new EmailAddress();
$toRecipientsRecipient1EmailAddress->setAddress('danas@contoso.com');
$toRecipientsRecipient1EmailAddress->setName('Dana Swope');
$toRecipientsRecipient1->setEmailAddress($toRecipientsRecipient1EmailAddress);
$toRecipientsArray []= $toRecipientsRecipient1;
$requestBody->setToRecipients($toRecipientsArray);
$requestBody->setComment('Dana, hope you can make this meeting.');
$graphServiceClient->me()->events()->byEventId('event-id')->forward()->post($requestBody)->wait();