Notifications are shown in two cases:
When the portal is open but you are on another tab or the browser is in background under another app which is in front.
When the portal is closed
In both cases the browser must be open.
Notifications are sent for the following events:
chat
channel message
incoming call
missed call
new voicemail
When you click on the notification popup it will take you to the browser’s tab with the portal. If there is no active portal session, the browser will open the portal in new tab.