Reoccurring Error w/Pokémon Transporter & Bank

Hello! Sorry as I don’t know what subreddit this question should go to, so I’m posting it where I think it might go.

I have a homebrewed Nintendo 3DS that I bought from Etsy. (Sorry if you think my purchase was a huge waste of money, I just don’t have the brain to learn how to do it.) I just recently connected it to a Nintendo Network ID in hopes of being able to transfer over Pokémon from games such as Pokémon Yellow, Blue, etc. The person who homebrewed my Nintendo 3DS said that many of his customers find success in being able to transfer their Pokémon but I am not finding that same success. Each time I log in Pokemon Transporter and select a game I am met with Error Code: 006-1204. So I’m left wondering what I did wrong? Is it because it’s homebrewed? I’ve tried to search for the answer but have not found anything so now I am here. Thank you!