You can reserve a product by placing an order, and selecting "Pick up from the store" at checkout. If you don't want to pay immediately, you can choose to pay via Klarna, which offers a 30-day payment period.
Once you have placed your order, you can pick up the products immediately during store opening hours by showing the order confirmation if the products are in stock. Alternatively, you can wait for an email confirmation that your order has been processed and placed on the pick-up shelf.
At this stage, you can still try the product and cancel your order if you wish. Find an available sales associate to cancel your order, or return the product at the checkout.