<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\Chats\Item\Messages\ForwardToChat\ForwardToChatPostRequestBody;
use Microsoft\Graph\Beta\Generated\Models\ChatMessage;
use Microsoft\Graph\Beta\Generated\Models\ItemBody;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new ForwardToChatPostRequestBody();
$requestBody->setTargetChatIds(['19:e2ed97baac8e4bffbb91299a38996790@thread.v2', ]);
$requestBody->setMessageIds(['1728088338580', ]);
$additionalMessage = new ChatMessage();
$additionalMessageBody = new ItemBody();
$additionalMessageBody->setContent('Hello World');
$additionalMessage->setBody($additionalMessageBody);
$requestBody->setAdditionalMessage($additionalMessage);
$result = $graphServiceClient->chats()->byChatId('chat-id')->messages()->forwardToChat()->post($requestBody)->wait();