The "On-site Messaging" section of the module contains configuration options and settings for Klarna On-site-Messaging. On-site messaging is a way to let customers know that Klarna is available on your website.
As of version 1.3.0+, On-site messaging is supported, for standard PrestaShop themes, such as Classic. Compatibility with non-standard themes is not guaranteed or supported.
The Client Identifier is found in the Klarna Merchant Portal, at Payments settings -> Client identifier, or also from "Conversion boosters" top menu -> On-site Messaging app -> Installation. Ensure you copy it without quotes or whitespace.
Klarna Merchant Portal -> Client identifier
Also, add your shop's domain in Allowed origins within Client identifier section.
Klarna Merchant Portal -> Allowed origin
Paste the Client Identifier from the Klarna Merchant Portal in the Client ID field in the PrestaShop Klarna module, in the "Credentials" section.
PrestaShop Back Office -> Klarna module Credentials
Determine which placement types are desired; product and cart page placements are recommended.
Data from the customer's browser for the shop (e.g. language and currency switcher) and shop data are used to determine the appropriate data-locale for the On-site messaging placement.
Positioning of the displayed on-site messaging placement(s) on the shop page are not currently configurable within the module. This functionality may be added in the future, but a target date is not yet available.