At the bottom of the plugin you will find the On-site Messaging configuration settings and options.
The data-client-id is found in the Klarna Merchant Portal, on the Installation page of the On-site Messaging app. Ensure you copy it without quotes or whitespace. Then, paste it in the Data client ID field in the Klarna plugin.
Select the checkbox to enable the Product or Cart page placement.
The placement data keys are found on the Placements page in the Merchant Portal. This is the Klarna messaging that will appear on your site. Once you find a placement you like, copy the name of the placement and paste it into the Product page placement data key or the Cart page placement data key field.
Select a location in the On-Site Messaging placement dropdown. This uses standard WooCommerce page locations, more information can be found in the FAQ.
Most Klarna placements have themes (light/default and dark) and some can be customized. If a placement is able to be customized, you will see a Custom design button for the placement, which you can see in the upper right of this example.
The choices in the Klarna plugin in WooCommerce equate to these options: Light = default, Dark = dark, and None = Custom design.
In order for our placements to meet accessibility standards, not every aspect of a placement can be customized fully.