Have you ever...?

Ever means from the time you were born until now. Except for rare exceptions, it can only be used in questions and to answers with a no.
It is used with have or had + a past participle.

Example:

Have you ever eaten a frog?

Has she ever gone to Australia?

When you answer the question, a yes answer will use have/has + past participle.

Have you ever seen a whale?

Answer:

Yes, I have seen a whale. or Yes, I have.

If you answer the question with a no, you will need to use

haven't /hasn't + ever + past participle or

have /has + never + past participle

(both of these have the same meaning)

Example:

Have you ever seen a whale?

Answer:

No, I haven't ever seen a whale. or
No, I've never seen a whale. or
No, I haven't.