save_token_hive.dart

  Future<void> saveUserToken(String token) async {
    try {
      //BOX_NAME is any string key for you box name.
      final secureKey = Hive.generateSecureKey();
      final encryptedBox = await Hive.openBox(BOX_NAME, encryptionKey: secureKey);
      await encryptedBox.put('token', token);

      //SECURE_STORAGE_KEY is any string key.
      await secureStorage.write(
        key: SECURE_STORAGE_KEY,
        value: json.encode(secureKey),
      );
    } on Exception catch (e) {
      throw CacheException(message: e.toString());
    }
  }