Devices will lose internet access during the process.
If you bought the device independently, you can manually upload firmware files. How to Update Huawei HG8145V5 Firmware Huawei Hg8145v5 Firmware Update
Instead of risking a brick by flashing unauthorized firmware, the best "update" for this device is to Devices will lose internet access during the process
Navigate to or Device Info . Look for a string like: V500R019C20S135 (R019 = older) or V500R021C00S170 (R021 = newer). Huawei Hg8145v5 Firmware Update