Sep 22, 2024 · Activating eSIM on AT&T prepaid. If your device requires a QR code to activate an eSIM, you'll need to purchase a prepaid eSIM kit in a physical store, such as an AT&T location, Walmart, or Target. If your phone supports converting physical SIM to eSIM (typically iPhones with iOS 15 or newer), you can follow these steps: Go to Settings. Tap ...