Navigate to from the top or side menu.
But remember: ISPs sometimes push "Stability updates" that actually cap your concurrent NAT sessions to reduce their server load. If your torrent speeds drop or your VPN fails after an update, they deliberately neutered your device. Zte Zxhn F670l Firmware Update
If the interface rejects the file you uploaded, you are likely trying to flash firmware meant for a different hardware revision. Navigate to from the top or side menu