There are open-source solutions like react-native-vision-camera that support both iOS and Android.

However, if you're looking for a more reliable solution that supports a wide range of barcodes, performs under challenging conditions (low-light, damaged barcodes), and comes with dedicated developer support, I'd recommend looking into a commercial solution, like Scanbot SDK (disclosure: I'm part of the team).

A colleague of mine actually wrote a tutorial for ReactNative, I'll leave it here in case someone wants to check it out. FYI: yes, we are a commercial solution, but we provide free trial licenses!