Security questions related
we don’t have sufficient information to reset security questions
iPhone 6s, iOS 12
Question marked as
Contact Support in the country where you live (and which is therefore the country on your account) and see if they can reset them for you : http://www.apple.com/support/itunes/ww (click on your country's flag, the country where you live, and which is therefore the country on the account ; click on Contact Support towards the top right ; click on Get Help under 'Talk To Us’)