If you have a cracked emulator, you can put any username and password in there as it doesn't make the slightest difference.
If however you don't have a cracked emulator, you need to get one. Otaku servers went offline ages ago, so you'd be more likely to be stuck by lightening 10 times a year than to get a license.
You need to have to files, Override.php and license.php you can find the Open Source emulator in the habbo->releases->server releases.
No need for such thing.