There are two main kinds of present perfect, the up-to-now present perfect, which is obligatory in both British and American English ('How long have you lived in London?') and the result present perfect ('I have finished my homework' = 'I am free'). It is this second present perfect that the British accuse Americans of being insufficiently addicted to the perfect. 'Ever' is associated with the perfect tense because it means 'at any time' and very often this means 'at any time up to now', in which case of course it needs a present perfect.good answer！
Forgive me, but I would say here the question focus on a difinitive period of time in the past. E.g "Did you ever take a taxi when you were in middle school". "Even one time" could apply to either "have you ever" or "did you ever ".Did you ever take a taxi? Here the question highlights the idea of "have you ever done this - even one time?