Fatal error when trying to use save feature of pokemon

Refer to my previous reply if you don’t have your own 3DS.

If you don’t own the game either (physical cartridge) then you imply that you have pirated the game (downloaded from the internet) which is illegal. If that is the case, we cannot help you.

Ebay should still have some 2DS or 3DS that you can buy. You will have to look around.