I bought [021501 MRC Loco Genie (steam heavy)].
I'd like to plug in the my steam.
The instructions say "if your loco has a 9 pin JST plug or NMRA 8 pin socket, you can simply unplug the original connector and plug in the decoder."
What kind of decoder does it fit?
I would like you to tell me the specific product name.
Not the best forum for this issue.
Use the Model Railroader DCC electronics forum. A few forums down. Very easy.
The General Discussion forum under Model Railroader shows you how to upload pictures which can be helpful.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.