Customers in store can still easily pay with Klarna using Shopify draft orders. Here’s how you can process an In-store order:
Create a Shopify draft order for a customer (with optional customer details prepopulated) with the desired products. Don't select Paid.
Email the invoice to the customer from the Shopify draft order admin page using the Send invoice button, either from the draft order or Payment due later order.
The customer then can pay for the draft order via your Shopify store's Online Store sales channel using your store's Shopify web checkout and choose Klarna or any other payment option available in checkout.
In summary:
Shopify doesn’t yet support Klarna to integrate directly into Shopify's Point of Sale sales channel.
Customers in store can still easily pay with Klarna using Shopify draft orders.