Forgot username and password of my 192.168.0.1

Hello, I want to setup my Fizz Router as Bridge mode for my other Wifi Router. but I completely forgot how to login in the 192.168.0.1 to make these changes.

I tried entering the username and password written on the router but it does not work.

I tried my WiFi name and password and it does not work either I dont understand.

Is there a way to only reset that username and password instead of completely reseting my Fizz Router?

Thanks