How can I remove Activation Lock from a used iPhone 13?

Don’t ask the seller for their Apple Account password. If they genuinely owned the phone, have them remove this specific device from their account while you’re present, then try another erase and restore. If they can’t or won’t do that, request a refund—the lock can’t legitimately be bypassed.

The seller needs to remove the phone from their Apple Account, not just toggle off Find My. They can do that through the Find My app or iCloud by selecting the iPhone, erasing it if necessary, and choosing “Remove This Device.” Once that’s done, restore the phone again and connect it to Wi‑Fi during setup.

If the seller claims it has been removed but the lock remains, the status may not have updated before you started setup. Restore it again after they confirm the device no longer appears in their account. If that still fails, ask for the original proof of purchase and contact Apple about Activation Lock support. Without the owner’s cooperation or valid purchase documentation, it may effectively be unusable.