How to add a notification center to my own app?

Good day.
I need to set up a notification button on my app’s navbar just like this forum does. This is a Vaadin component called Notification Center, but I haven’t been able to find any information or download about it, and my client wants exactly the same feature on the application.
Is this possible?

Thanks in advance.



I guess you could just have a Button that opens a Window. Some custom styles are needed to make it look nice, but nothing too complicated.