Subscription Purchase in iOS

My app contains subscription based functionality for purchase. So which way I require to move ahead into this. When I search for this in Google, I always found Consumable and Non-Consumable related product purchase related source code.

I want to move ahead with Renewable Subscription purchase. At present i have Prime31 plugin with following source code written:

Code (CSharp):

1. #if UNITY_ANDROID
2.          var productId = GameConstants.SKU_PURCHASE_9999_COINS;
3. ////        var productId = GameConstants.SKU_ANDROID_TEST_PURCHASE;
4.          #elif UNITY_IOS
5.          var productId = GameConstants.SKU_PURCHASE_9999_COINS;
6.          #endif
7.          IAP.purchaseConsumableProduct (productId,  (didSucceed, error) => {
8.              Debug.Log ("purchasing product " + productId + " result: " + didSucceed);
9.              if (didSucceed) {                  
10.              }              
11.          });

Whether same code, Can I use for Subscription purchase? What is alternative way for me to implement Subscription purchase?

 

Now at least I found a way to purchase and restoring a Subscription in Unity.

https://unity3d.com/learn/tutorials/topics/ads-analytics/integrating-unity-iap-your-game

After this implementation, I got another doubts in mind:

• How to get expire time at every launch of game?
• How to validate receipt with Apple server?

I have watched this video and they are explaining all process but this video was in core iOS platform.

Now something similar I want to do with Unity so what is a way for this?