Apple Pay - How we can check subscription updates

Hello, we recently added Apple Pay to our application, and we have some controls for subscriptions with transactionId. I have a question: If a user updates their subscription via the App Store, can we still use the same transactionId, or should we take another approach? Thank you.

Why any apple employee don't help to me I really wonder you guys have worst documentation in the world why I have to fight with your apis every day? I never had a problem with google pay api's but I always have problem with apple stacks thank you :)

Apple Pay - How we can check subscription updates
 
 
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