Hi,
Dashboard is what you see when you enter the app on your device (it's a list of features beginning with Virus Scanner) - you might need to scroll down a bit to find the App Locking. Once there, you might either unlock your Whatsapp (you'll most probably be asked for a PIN while doing so) or go to settings (icon in the action bar - top right) and disable App Locking completely. Now this disables the feature itself, but not the notifications you get while installing/updating some of the apps we think deserve locking. If you want to disable those as well, go to the Dashboard again and either click on the three dots in the top right corner or tap on the loho in the top left corner. Either way, you'll see Settings there, after tapping it, you'll see a pretty long list of settings. Scroll down, find "Disable advisory notification" and check it.
Filip