Dynamic Authorization and Asynchronous Authorization
What is Dynamic Authorization?
In e-commerce, slow response times cause users to leave, so response time is important while accurate authorization/review requries certain amount of time. Therefore, depending on the payment method, transactions that could have been approved may be declined without enough time to review transaction thoroughly. That means an opportunity loss.
In Amazon Pay, if such transaction is deemed requiring longer review time (not all transactions, but only those deemed required), it automatiaclly swtiches to "strict review mode" that reviews transaction for 24 hours at max, which is called "Dynamic Authorization" to prevent opportunity loss as much as possible.
What is Asynchronous Authorization?
Amazon Pay performs "strict review mode" with 24 hours for all transactions without exception. Asynchronous authorization state starts with "Authorization Initiated", and authorization result will be returned within 24 hours.
How to set up?
In either case, you will set canHandlePendingAuthorization=true to the transaction.
You can set this parameter in UpdateCheckoutSession and CreateCharge API, and depending on API and it's chargePermissionType, Amazon Pay performs either Dynamic Authorization or Asynchronous Authorization.
Please refer to FAQ in Japanese - When do I beter set canHandlePendingAuthorization=true? for more detail.