To update a single user attribute, call `updateUserAttribute`:

```dart
Future<void> updateUserAttribute() async {
  try {
    final result = await Amplify.Auth.updateUserAttribute(
      userAttributeKey: CognitoUserAttributeKey.email,
      value: 'email@email.com',
    );
    if (result.nextStep.updateAttributeStep == 'CONFIRM_ATTRIBUTE_WITH_CODE') {
      var destination = result.nextStep.codeDeliveryDetails?.destination;
      print('Confirmation code sent to $destination');
    } else {
      print('Update completed');
    }
  } on AmplifyException catch (e) {
    print(e.message);
  }
}
```

To update multiple user attributes at a time, call `updateUserAttributes`:

```dart
Future<void> updateMultipleUserAttributes() async {
  const attributes = [
    AuthUserAttribute(
      userAttributeKey: CognitoUserAttributeKey.email,
      value: 'email@email.com',
    ),
    AuthUserAttribute(
      userAttributeKey: CognitoUserAttributeKey.familyName,
      value: 'MyFamilyName',
    ),
  ];

  try {
    final result = await Amplify.Auth.updateUserAttributes(attributes: attributes);
    result.forEach((key, value) {
      if (value.nextStep.updateAttributeStep == 'CONFIRM_ATTRIBUTE_WITH_CODE') {
        final destination = value.nextStep.codeDeliveryDetails?.destination;
        print('Confirmation code sent to $destination for $key');
      } else {
        print('Update completed for $key');
      }
    });
  } on AmplifyException catch (e) {
    print(e.message);
  }
}
```