Implement web push in laravel - laravel-8

Question

I m trying to implement web push notification in my laravel application and I have setup web push for laravel by follow along the tutorial from the tutorial below
https://medium.com/#sagarmaheshwary31/push-notifications-with-laravel-and-webpush-446884265aaa
but there are still some question that I am not understand
Why we need the push_subscription in database ? It seems like I not even used it elsewhere ?
laravel notification not working ( if i did like this )
$users = User::whereIn('id', $vendor_user_ids)->get();
Notification::send($users, new WebChatPushNotification($chat));
but it work if I use Notification::send(User::all(), new WebChatPushNotification($chat));
since both of them are also a collection of user model, but why the latest one work.
and is there any other tutorial that can explain about web push more better that are recommended ?
Oh ya, for your information, I am using Laravel 8 and laravel-notification-channels/webpush package
Thanks in advance!

Answer 1

Finnally, I managed to solve it by myself.
the package itself will need to query the user's endpoint from the table when we try to notify the user.
Notification wont show because my $users is null, so nobody will be notify. such a silly mistakes, sorry for trying to ask such silly question here.