Hi friend.
HG658b is a carrier product.
We are not authorized to download or provide the firmware for the HG658b device.
Device firmware is usually not released on the network because it involves network security.
If you need device firmware, you can obtain it from your device provider.
For details about how to obtain the firmware, see the following link:
How to get the firmware or software of Huawei ONT
I hope I can help you!