When you touch and hold a notification on the status bar, three options may appear “Priority”, “Default” and “Silent”.
Select “Priority” to show at the top of conversation notifications and as a profile picture on lock screen, appear as a bubble, interrupts Do Not Disturb.
Select “Default” may allow ring or vibrate base on device settings.
Select “Silent” to mute all notifications from this app
You can go to “Settings”->“Apps” ->“View all apps”->select the app you want to set->“Notifications” to take advantage of additional set up options.
Note: Available settings and menus may vary depending on device model and software version.