Can't access admin login after logging in and changing the password and username , now I can't login again. Help pls .

I decided to change my mifi’s admin username and password. after that, i tried logging back to it and just realized that I can’t log back into my admin mifi account using the...

#reset my login details as I forgot my username and password

I logged in and changed my default login details but I can’t remember the new username and password.