At this time, we don't have an option for in-store checkout. We are hoping to be able to integrate with a physical POS system soon!
However, we have found great success with being available for checkout on the online store for brick-and-mortar shops, through the "in-store pickup" option. If a customer was in-store and wanted to check out with Sezzle, they could check out online through your site, select in-store pickup and check out online with Sezzle. They can then pick up their merchandise right there in the store. Please work with your e-commerce platform to set up that shipping method as an option, should you like!