Click the in your tray menu and click the icon
Click on Preferences
Go to App Preferences
Un-check Show pop-up notifications (check if you want it enabled)
Notification once a file is updated?
Is there a way to permanently block "Shared with me" files from asking to be sunc to desktop?
Shared with me nuisance
How to disable balloon notifications [SOLVED]
Insync no longer autostart Mac