Stemo is the shop you already run, given a storefront patients and neighbours can open without walking in.
The customer scans the UPI QR that already sits by your billing machine. You see it in your bank app. Cash on delivery and khata if that is how the street works.
No. You are the retailer. Stemo is the counter software.
No. Link or QR.
A trial, then a flat fee. Details on the pricing page.