Parse error: syntax error, unexpected 'Request' (T_STRING), expecting ')' [on hold]

public function store($channelId Request $request)
{
    $thread = Thread::create([
        'user_id' =>auth()->id(),
        'channel_id' =>request('channel_id'),
        'title' =>request('title'),
        'body' =>request('body'),

    ]);
    return redirect($thread->path());
}

I have added the $channelId In store method and it is give me the error any sloution for this will be appreiciated.

via Chebli Mohamed