Deleted application on Macbook still shows notification.

I've deleted the Loopback application a while back but whenever I shut down and turn on my Macbook, it keeps showing the notification to update the app. Took a chance by clicking 'update' but nothing happened. Also checked whether the app was still in the application folder and it isn't. Under notifications in system preferences, it does show loopback but I do not want to simply turn it off since it would still be there. Your help would be appreciated, thanks!

Mine is a MacBook (Retina, 12-inch, Early 2015).