Every time I try to install an app from App Store into my iPad 3 running on IOS 6, I can view a pop-up box along with a message saying “Improve your Apple ID security”. It gives me two options viz ‘Not Now’ and ‘Continue’. If I tap on ‘Not Now’, the pop-up will disappear without showing any noticeable issues. In case I make a single tap on ‘Continue’ option, it will ask for Apple ID and password even after entering them several times. How can I fix up this issue?