If you purchased a "MAC activation," you cannot use a Username/Password. You must use an app like STBEmu and enter the specific MAC address provided. Changing the MAC without telling your reseller will break the activation.

Keep a record (screenshot or note) of device names and activation dates so you can quickly revoke access if needed.

Open the on your Android TV, Nvidia Shield, or smartphone.

If a seller gives you only a 6-digit number, ask for clarification. True activation codes are longer and contain letters and symbols.