requireInteraction: true

Push me to open a requireInteraction=true notification!Push me if you are done

Steps:

1. Make sure you didn't block the notification permission.
2. Allow the notification permission if the prompt opens.
3. Click the first button.
4. See whether the notification disappears from the screen without interaction. It must not.
5. If you are sure it's not disappearing, then click that second button.

Why this is manual? Because

1. One need to wait for more than arbitrary platform-specific time to see it really does not disappear automatically.
2. There's simply no API to tell it's disappeared from the screen or not