Huawei does not directly host consumer firmware, but some local carriers provide official downloads:
Frequently found on Dialog Sri Lanka devices. Hardware Version: WL1B310CM. How to Download and Update B310s-925 Firmware Download
Provides original locked firmware for restoration purposes. Huawei does not directly host consumer firmware, but
Installing the wrong firmware (e.g., for a different model like B310s-927 or a different hardware version) will brick your router (make it unusable). Proceed only if you know your current firmware is corrupted or you need a specific feature. B310s-925 Firmware Download