How to open app settings page in react native android?

You can use @react-native-community/react-native-permissions library.

Here offical documantation: https://github.com/react-native-community/react-native-permissions#opensettings

Example:

import { openSettings } from 'react-native-permissions';
openSettings();

You can open your app settings by using Linking library.

import {Linking} from 'react-native';

Linking.openSettings();

Offical document: https://reactnative.dev/docs/linking#opensettings