If the "Upgrade" button is missing, your ISP has likely disabled manual updates. You may need to contact their support for the latest version. Default Credentials: doesn't work, try with the password

Zte F670l | Firmware Update Upd Install

If the "Upgrade" button is missing, your ISP has likely disabled manual updates. You may need to contact their support for the latest version. Default Credentials: doesn't work, try with the password