Here you can find a high-level description of how Order management works.
When your customers pay with Klarna and their orders are created, you need Order management to finalize the purchase journey. With this solution, you perform different order operations before, during, and after fulfilling the order.
Here’s an overview of the order management operations:

Order management integration.
You can manage orders through a set of server-side calls. They can be grouped into 3 main categories:
View and change orders
This category includes the following requests:
Use only getOrder endpoint when it’s strictly required by your business logic. Don’t rely on this operation to confirm that an order was placed or that other operations succeeded. Instead, use the responses returned by each operation itself—if an operation returns a successful response, you can consider it successful.
Capture and track orders
This category includes the following requests:
Refund and extend orders
This category includes the following requests: