about restore purchases : anonymous id, addPurchaserInfoUpdateListener vs restoreTransactions

Hello, I have an inquiry regarding the addition of the "Restoring Purchase Products" function. (Appstore has rejected the assessment that it does not have a purchase restore function.)

What I'm curious about is

1.
I wonder if I can use "Anonymous App User IDs".
I wonder if I need to designate a user ID.


2.
Purchases.addPurchaserInfoUpdateListener(
(purchaserInfo) async {
final purchaserInfo = await Purchases.getPurchaserInfo();
...
}

and

PurchaserInfo restoredInfo = await Purchases.restoreTransactions();

I'm curious about the difference.
If the method is different, is there a code to refer to?
I am inquiring because it seems to bring the same purchase information.

Thank you for reading it.


- Notes
. flutter app
. Purchase or restore purchase after SNS log-in
. We do not share subscriptions between platforms.