Piece shows in wrong place

Sorry, there's nothing you can do because that's right as it is. Your opponent used a move called en passant on you. Here's an example of how it works:
There are a couple of good articles on en passant on this site which could explain this a lot better than I can. Good luck on the rest of your game and welcome to chess.com!
I can give a picture if you need it, but this may be good:
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It has my opponent taking my pawn at d6. ???? I'm supposed to be at d5. Is there anything I can do to get that fixed?
Thanks :) I'm new!