The Klarna Payments for PrestaShop module can be downloaded from here.
Once installed and activated, the module's settings can be found by selecting Configure next to the Klarna Payments module in your store's Module Manager.
SSL certificates are required for all of your interactions with Klarna APIs.
Test mode allows you to test your integration to ensure it is working properly before taking real orders, and is the default setting. Orders placed while in test mode will not cause any real money to be exchanged. Moving the switch next to Live mode to Yes enables live (production) mode and orders that are placed in live mode are real, valid orders. You can sign up for test credentials here.
API endpoint specifies the region your credentials are valid for (EU, US, or OC). Merchant type determines the type of customers that are eligible to use Klarna Payments on your store, business to business (B2B) or business to customer (B2C), and is also determined by your contract with Klarna.
You can generate your Klarna API credentials in the Settings app of the Klarna Merchant Portal. These will consist of a username and password.
Once generated, you will enter these credentials in the Username (UID) and Password fields.
If you generated test credentials following the above link, you will enter these in the Test Klarna API username and Test Klarna API password fields.
Make sure you click Save at the bottom of the page when you are finished.
For information on the other tabs in the module's settings, continue to the Detailed page.