How do I add the Klarna API credentials to my Shopify store?

For Shopify stores, Klarna API credentials are entered in 2 places under your Shopify admin. The Klarna API credentials must match exactly in both of these places:
In the Klarna payments app (under apps)
In Klarna alternative payment method(s) (Settings > Payments > Alternative payment methods)
We recommend copying and pasting your Klarna API credentials to eliminate typos, and make sure you don’t copy any extra spaces.
For more information, check out our step-by-step guide for Shopify retailers.