How to create pop-up from app-locker before uninstalling any respective app?

[waleed akmal]

I am using SAMSUNG S8 PLUS ,in which i am facing some problems regarding authentication before uninstalling any app.Whenever i unintentionally or accidentally tried to uninstall an app.My app locker doesn't gives me any popup regarding (Are you sure you want to uninstall this app)?
Kindly help on this issue if anyone knows how to?
My android version is 7.0 Nougat