Never attempt a firmware upgrade over Wi-Fi. A sudden drop in wireless signal can corrupt the installation. Connect your computer directly to the ONT using an Ethernet cable.
Your ISP is the primary source for the correct firmware tailored to their specific network configuration. Huawei Enterprise Support: huawei hg8145v5 firmware download install
Overview
Click "Browse" and select the firmware file you downloaded. Install: Click the Upgrade button. Never attempt a firmware upgrade over Wi-Fi
publicly available for direct download on consumer sites. It is restricted to the following channels: Internet Service Providers (ISPs): huawei hg8145v5 firmware download install