Android Question Please how to create custom layout notifica. How can I start!

There are NB6 and NotificationBuilder( it's also deprecated) that are used to create Notification but because we should use only NB6 we can't create custom layout notification. Only NotificationBuilder permittes us to do that but it's old and not used.

I've seen some youtube tutorial in Android Studio but it requires RemoteViews but it's not so easy to understand at first time.

Please can anyone that can explain me how to start with custom notification??? Can I have some example or not?

I know that here I'll be able to find something but HELP ME!!!

Thanks for all comunity!

Video that I saw: