You cannot install the wrong software. Before searching for an update, log into your router to see what you currently have.
To update the software (firmware) on your router, you can use the web management interface. This process ensures your device has the latest security patches and performance improvements. Updating via Web Management Page Update Software in HUAWEI HG531 v1
Note: Sometimes a backup from old firmware is incompatible with new firmware. Do not automatically restore it; save it only for emergency rollback. You cannot install the wrong software
If you have a legitimate firmware file (usually ending in .bin ): Update Software in HUAWEI HG531 v1