<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Users\Item\Todo\Lists\Item\Tasks\Item\Attachments\CreateUploadSession\CreateUploadSessionPostRequestBody;
use Microsoft\Graph\Generated\Models\AttachmentInfo;
use Microsoft\Graph\Generated\Models\AttachmentType;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new CreateUploadSessionPostRequestBody();
$attachmentInfo = new AttachmentInfo();
$attachmentInfo->setAttachmentType(new AttachmentType('file'));
$attachmentInfo->setName('flower');
$attachmentInfo->setSize(3483322);
$requestBody->setAttachmentInfo($attachmentInfo);
$result = $graphServiceClient->me()->todo()->lists()->byTodoTaskListId('todoTaskList-id')->tasks()->byTodoTaskId('todoTask-id')->attachments()->createUploadSession()->post($requestBody)->wait();