Is it possible to test an iOS subscription before the subscription product gets approved by Apple?
 

This is my first time submitting to the app store, I got denied because they said my app did not function when the “purchase” button is pressed. But I am wondering, how would the in-app purchase pop-up be able to display without the product being approved?

For example, if I push it to testflight, no one would be able to click the button because it is not an approved product, and I believe that is what they are testing when approving the app.