There is a way to edit the time of a notification from web page is shown?

Let me explain. I have a web page that send notifications to my users when they get a new message.

I do it with push notification and it works fine but, my users are asking me that the time show of the notification is too slow, that it disappear too fast.

There is a way to maximize the time of the notification to make it be showed like 20 seconds if the user has not interacted with it yet?

If not by code, there would be a way to create a chrome or firefox plugging to make this real?