How can i send message to group chat rather than user id ?

[thavornc]

Could I please know how to send message to group chat (thread id) as the similar request below,
$test = [
'recipient' => [
'thread_key' => '<THREAD_ID>',
],
'message' => [
'text' => 'hello, world - group chat!'
]
];

I understand that a send method $bot->send('', 'text message.')); call 'recipient' ==> 'id' always.
$test = [
'recipient' => [
'id' => '<Sender_ID>',
],
'message' => [
'text' => 'hello, world!'
]
];
so is there a way to call the method as $bot->send('<thread_id>', 'text message.'));