The reason is that “Professor Layton and the Last Specter” runs on a DS, although has a secret door that needs a password specifically set to a specific DS, meaning someone else’s password won’t work. However, in order to get the password, you need to get the sequel, but the sequel is made for a 3DS, as said in the game itself. If I play it on MelonDS, I can’t get the password since the sequel, “Professor Layton and the Miracle Mask” is run on a 3DS, meaning I have to use Citra.
In order for us to provide better support, we need to see the log generated by citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File
Citra does not have the capability of launching NDS titles (the 3DS uses separate hardware for that, so we’d have to write a new emulator to support this basically).
Thus this isn’t possible to emulate currently.
You can’t use 2ds games or gba games i think, maybe try a different software
2DS games are 3DS games.
NDS games are what you’re thinking off.