The question is about the "Login with Amazon" user id in form of amzn1.account.A123456789.
(1) For one user, is this user id the same for all web sites using LWA? Oder does each registered web site get a different user id from Amazon for the same user?
(2) For one user, is this user id the same for "Login with Amazon" and for "Pay with Amazon"? or are there two different ids for one user?
I am asking because we are porting an existing shop database to a new web shop system. We thought (hoped) that we can use the existing Amazon IDs from the old database to identify the users in the new system. But first tests show that the ids are different.
What's also confusing is the documentation [https://developer.amazon.com/de/docs/login-with-amazon/customer-profile.html]
It reads:
Every company that creates websites or apps for Login with Amazon gets the same user_id for a customer. However, when a customer logs in to another company's app or site, the user_id will be different. This is so user_id cannot be used to track customers across the Web.
For me, both sentences are contradictory.
(1) The User IDs are not identical between different merchants. If you use the same merchantId for the new system, you should get the same User IDs.
(2) Login and Pay User IDs are the same