Anytime vs any time

Let me preface this by saying I already did some research regarding the proper usage of anytime and any time. However, I came across a question in a quiz in this article https://www.dictionary.com/e/anytime-vs-any-time/ that confused me a bit.


Here: Any time/anytime I want to relax, I just step outside and breathe the fresh air

From what I've learned in the article, "anytime is an adverb that can replace whenever" so I assumed that anytime would be the correct answer in this question since it can replace the word whenever in the context. "Whenever/anytime I want to relax, I just step outside and breathe the fresh air." However, my answer was wrong and the correct one is "any time". Now, this leaves me wondering why this is the correct answer. Can someone help me?

I've also seen some examples in this article https://prowritingaid.com/any-time-vs-anytime that confused me.

Here: any time I see an old-fashioned teaspoon, I buy it for my nan who collects them.

The students will be able to do the triple jump correctly any time now.