Masalah tidak bisa post id group ke table message

aku lagi bikin chat pake Framework Laravel, Vue.js dan Pusher, singkat cerita aku sudah bisa nampilin nama groupnya dan get data messagenya di kolom chat, masalahnya saat di post pesannya malah group_id nya undefined

get message

Route::get('/groups/{groupId}', function($groupId) {
	$authUserId = Auth::user()->id;
	$output = DB::table('messages')
		->leftJoin('users','users.id',	'=',	'messages.user_id')
		->join('groups','groups.id','=','messages.group_id')
		->where('messages.user_id','=',$authUserId)
		->where('messages.group_id','=',$groupId)
		->orWhere('messages.user_id','!=',$authUserId)
		->where('messages.group_id','=',$groupId)
		->select('users.name as user','users.image','users.image_path','users.id as userId','groups.id as groupId','messages.message','messages.file_path','messages.file_name','messages.type','messages.created_at as time')
		->orderBy("messages.id","asc")
		->get();
	return $output;
})->middleware('auth');

utk post ke table message

Route::post('/groups/{groupId}', function($groupId) {
	$user = Auth::user();
	$message = $user->messages()->create([
		'message'=>request()->get('message'),
		'type'=>request()->get('type'),
		'group_id'=>$groupId,
	]);

	// new message has beed posted
	broadcast(new MessagePosted($message,$user,$groupId))->toOthers();
	$output['message'] = $message;
	$output['user'] = $user;
	return ['output'=> $output];
})->middleware('auth');