Get and save your Klarna API credentials: a. Go to the Settings section in the Merchant portal. b. Download and open the file. The Klarna API credentials consist of a Username and password and you'll need them in the next step.
Connect Klarna to your Wix store: a. Navigate to the Accept Payments tab within your dashboard settings. b. Click on See More Payment Options > Connect next to Klarna. c. Enter your Klarna API credentials (username and password) and click on Connect.
For detailed documentation of Klarna payments for Wix, see here.
In summary:
To install Klarna payments in your Wix store, you need to log into the Klarna Merchant portal with your Klarna Merchant account.
Then, get and save your Klarna API credentials from the Merchant portal.
Finally, connect Klarna in your Wix store's dashboard settings.