Technically, HPP is a companion service to Klarna Payments or Klarna Checkout, which can both be referred as a Payment Provider. You will have to integrate one of these APIs to create a Payment Session, and then use HPP to deliver the Payment experience to your consumers.
A complete payment session will involve three of Klarna services:
A different integration guide is available for both platforms.
In this document, the term Payment Provider refers to either Klarna Payments or Klarna Checkout and Payment Session refers to the corresponding KP Session on Klarna Payments or KCO Order on Klarna Checkout.
The overall integration sequences between the backend of the integrator, the Consumer and Klarna depends on the use case (ie eCommerce, In-store or Telesales) as all interactions depend on the distribution mechanism and how the status of the HPP Session is read.
This diagram shows the common step between these integrations. Also, depending if it is a Klarna Checkout or Klarna Payments integration, calls will be different.