I haven’t made that mistake, but I did accidentally list a 3 credit course as a 1 credit course and I had already submitted my app when I noticed it.
It had a minuscule effect on my GPA and it wasn’t a prerequisite, so I didn’t sweat.
If you haven’t submitted your app, then you can still correct your mistake. However, if you’ve submitted it and the school has already verified it, then unfortunately, you can’t do anything about. If this is the case, then I would contact the schools and make them aware of the mistake.
Hope this helps.