Vincular identidades de usuario - React Native SDK

import React, {useEffect, useState} from 'react';
import {
  FlatList,
  Pressable,
  StyleSheet,
  Text,
  TextInput,
  View,
} from 'react-native';
import {Credentials} from 'realm';
import {
  AppProvider,
  UserProvider,
  useApp,
  useUser,
  useAuth,
  useEmailPasswordAuth,
  AuthOperationName,
} from '@realm/react';

export const LinkIdentities = () => {
  return (
    <AppProvider id={APP_ID}>
      <UserProvider fallback={LogIn}>
        <RegisterUser />
      </UserProvider>
    </AppProvider>
  );
};
// Log in an anonymous user. This component only mounts
// if there is no authenticated user.
const LogIn = () => {
  const {logInWithAnonymous} = useAuth();
  return (
    <View>
      <Text>No one is logged in yet.</Text>
      <Pressable
        onPress={logInWithAnonymous}>
        <Text style={styles.buttonText}>Log in</Text>
      </Pressable>
    </View>
  );
};

type UserIdentity = {
  providerType: string;
  id: string;
};
// Link an anonymous user to an email/password identity.
// For this example, the App Services backend automatically
// confirms users' emails.
const RegisterUser = () => {
  const app = useApp();
  const user = useUser();
  const {logOut} = useAuth();
  const {register, result} = useEmailPasswordAuth();
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [userIdentities, setUserIdentities] = useState(user.identities);
  // Use `result` to react to successful registration
  // by linking credentials with the current user.
  useEffect(() => {
    if (result.operation === AuthOperationName.Register && result.success) {
      linkCredentials();
    }
  }, [result]);
  if (!userIdentities.length) {
    setUserIdentities(user.identities);
  }
  const linkCredentials = async () => {
    const credentials = Credentials.emailPassword(email, password);
    await user.linkCredentials(credentials);
    setUserIdentities(user.identities);
  };
  const registerAndLinkIdentities = async () => {
    register({email, password});
  };
  const deleteUser = async () => {
    app.deleteUser(app.currentUser!);
  };
  return (
    <View>
      {/* Show all identities associated with the current user */}
      <FlatList
        data={userIdentities}
        renderItem={({item}) => (
          <Text >ID: {item.id}</Text>
        )}
        keyExtractor={item => item.id}
      />
      <Text>Link anonymous user with email/password account</Text>
      <View>
        <TextInput
          onChangeText={setEmail}
          value={email}
          placeholder="email..."
        />
        <TextInput
          onChangeText={setPassword}
          value={password}
          placeholder="password..."
        />
      </View>
      <View>
        <Pressable
          onPress={registerAndLinkIdentities}>
          <Text style={styles.buttonText}>Register</Text>
        </Pressable>
        <Pressable
          onPress={logOut}>
          <Text style={styles.buttonText}>Log out</Text>
        </Pressable>
        <Pressable
          onPress={deleteUser}>
          <Text style={styles.buttonText}>Delete user</Text>
        </Pressable>
      </View>
    </View>
  );
};