laravel Notification Undefined index: user_id - laravel

Question

I going to do massage notification, I already make the notifications steps,
but gives me this error
when I do dd($notifiable); I found all data
Undefined index: user_id OR
Undefined index: name
public function store(Request $request)
{
$chating=new chats();
$chating->chat = $request->input('chat');
$chating->user_id = Auth::id();
$chating->employee_id = $request->input('employeeid');
$chating->save();
$user_id=$request->input('employeeid');
auth()->user()->notify(new SendMassages($user_id));
return redirect()->back();
}
database notifications table coulmn data {"user_id":5,"name":"Ibrahim"}
Model
protected $user_id;
protected $name;
public function __construct($user_id)
{
$this->user_id = $user_id;
}
public function via($notifiable)
{
return ['database'];
}
public function toDatabase($notifiable)
{
return [
'user_id' => $this->user_id,
'user'=>$notifiable
];
}
View:
{{ $notification->data['name'] }}
Model:
class SendMassages extends Notification
{
use Queueable;
public $user;
public $user_id;
public function __construct($user_id)
{
$this->user_id = $user_id;
}
public function via($notifiable)
{
return ['database'];
}
public function toDatabase($notifiable)
{
// dd($notifiable);
return [
'user_id' => $this->user_id,
'user'=>$notifiable
];
}
}

Answer 1

It seems that you have problem with encapsulation in your code. First you have to make the property of your model into public if you want the quick and not-safe way but if you want the OOP way, You must write setters to do that logic for you.
First and not-safe approach :
class YourModel {
public $user_id;
.
.
.
}
The OOP way:
Class {
public function setUserId(int $userId)
{
$this->user_id = $userId;
}
.
.
.
}
if you are willing to get the exact answer please copy your controllerclass and model in here.