private String decrypt(String nonce, String associatedData, String ciphertext) throws Exception {

       byte[] keyBytes = this.apiV3Key.getBytes();

       byte[] nonceBytes = nonce.getBytes();

       byte[] associatedDataBytes = associatedData.getBytes();

       byte[] ciphertextBytes = Base64.getDecoder().decode(ciphertext);

       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");

       Key secretKey = new SecretKeySpec(keyBytes, "AES");

       GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, nonceBytes);

       cipher.init(Cipher.DECRYPT_MODE, secretKey, gcmParameterSpec);

       cipher.updateAAD(associatedDataBytes);

       byte[] decryptedBytes = cipher.doFinal(ciphertextBytes);

       return new String(decryptedBytes);

}