BEFORE YOU RESET THE ROUTER..
Have you determined that the SSID is not broadcasting by doing a scan from your computer?
Does anyone else have access to this router to change the settings?
If no, then we need to determine if the router has really changed.
If yes, then you need to talk to the person that made the changes.
CAUTION - making changes to the router may make it impossible to get on the internet. You may not even be able to access the router without making changes to your computer. Unless you know what you are doing, I wouldn't recommend it.
If you are sure you want to get to the router and make changes
To get to the router-
Have you tried a default password?
It looks like
username - admin
pwd - admin
is the most common one for HUAWEI routers.
It looks like there might also be a back door to get your router depending on the model.
Try that user and password and see if that gets you into the router.
Without a model number, I can't be more specific. HUAWEI makes several models.