How to detect Recurring Payments against a subscription using webhooks

I am using resthook ‘invoice.payment.add’ to detect when payments are being made against subscriptions.
I am able to get the ‘transaction id’ as part of resthook api payload, using that ‘transaction id’ i use GetTransaction Api Endpoint to fetch the transaction object.

There is no place in the documentation to tell us what values are expected in the fields of a transaction object?
I’m Following this
From the Transaction Object , is it possible to get the Original Order Id that was created when subscription to the product started. I see fields order_ids, Order Array, and order_items within it. are they new order ids generated for current payment, or any of these fields can give me original Id.
From the transaction object, is there any field that will get me ProductSold value (id of the product against which payment was made)
what are possible value of status field in a transaction object.
is there a better way to identify when recurring payments against a subscription plan are successful through API & resthooks? and how to relate these successful payments to Original orderIds & Product solf