Yes, Wix users can manage payment methods offered by contacting the Klarna merchant support team. Head to https://klarna.com/merchant-support to get the appropriate regional contact information.
Approval of customer orders is dependent on the location and currency offering of the Wix site, e.g. for a Klarna merchant account created with EUR currency, an order with a US customer billing address will not be accepted by Klarna and the customer can instead choose another payment method.
No, Wix does not currently support multi-currency; sites can only have one currency per store. Klarna will only accept orders for customers whose billing country matches the store's single currency.
No, not all Klarna payment methods are available out of the box. This is region/country specific. Klarna merchant support can assist with determining which products are available in each location for Wix users, e.g. the UK requires an actual lending license to offer financing.
All Wix transactions are auto-captured (immediately after the order is placed). Thus the payout delay set by Klarna for Wix merchants is 11 days.
Based on your Klarna contract, Klarna charges merchant fees for captured orders. Since orders are automatically captured, Klarna fees will apply for each order, even if the order is cancelled in the Wix admin without being fulfilled.
All Wix orders are currently auto-captured immediately after the order is placed, not when the Wix order is fulfilled. Thus customers start their payment(s) to Klarna when the order is placed and captured, not when the Wix order is shipped/fulfilled. Auto-capture also impacts the defaulted payout delay for Wix merchants.
Specific to the direct bank transfer payment method available in European regions, there is currently a known issue where if the customer closes their browser window after authenticating with their bank but before fully completing the Klarna payment, the order can be created in Klarna, but not in Wix. We are monitoring data to fix these orders manually ongoing until a fix is in place. For merchants with previously impacted orders, please open a Wix support request for the Wix support team to manually approve affected transactions.