Are you on the latest Windows App version? If so, if you log in and visit the device page, there should be a settings cog in the top right corner. Tap that and click notifications, you should see a volume slider. Hope this helps!
Are you on the latest Windows App version? If so, if you log in and visit the device page, there should be a settings cog in the top right corner. Tap that and click notifications, you should see a volume slider. Hope this helps!