tracking purchased subscription outside the app(ios)

what happens if user buys a subscription pack outside app(via settings>iTunes & app store). once purchased on launching the app does purchase process gets called? how can track the subscription purchase made outside the app?

 

@anil_uk This link should help. Look for the section towards the bottom of the page regarding iOS promotional purchases https://docs.unity3d.com/Manual/UnityIAPiOSMAS.html