Have you tried the forum search? There are several solutions. I think there's no library you can use in both platforms, but there's solutions for ios too.
yes I searched the forum and I saw a solution for android that used the "Barcode Scanner" app, but for android, for ios I haven't seen a similar one.
I was looking for a solution that could be used for both Android and iOS, and not two different solutions
There cannot be a solution for both as both are using a different programming language.
Honestly i can´t remember seeing any Library which works in Android AND iOS. And i don´t think there is one.