You cannot download a random .bin file from the internet and flash it. The HG8245Q2 is region-specific and ISP-locked in many cases. Follow these steps to know exactly what you have.
Look for these specific fields:
. If a new version is available, follow the prompts to install it. Option 2: Manual Update via Web Interface Hg8245q2 Firmware Update
If your ISP owns the ONT (leased equipment), updating the firmware violates your terms of service and may incur a replacement fee. You cannot download a random