Hmac256 Signature invalid error Google App Script

Question

I am attempting to retrieve trades from a service called 3Commas in Google Apps Script. I've worked with public endpoints before, but this is the first time I've attempted to work with signed endpoints. I'm currently receiving an error that states:

[19-01-09 16:46:24:592 EST] {"error":"signature_invalid","error_description":"Provided signature is invalid"}

I'm guessing this is a formatting issue on my part. I'm using jsSHA to build the HMAC part. I've tried following the example in the docs. But I haven't quite got it yet. Any suggestions on what it could be?

3Commas Docs: https://github.com/3commas-io/3commas-official-api-docs#signed--endpoint-security

function main() {
  var key = 'apikey';
  var secret = 'apisecret';

  var baseUrl = "https://3commas.io/public/api";
  var endPoint = "/ver1/smart_trades";
  var pointParams = "?limit=10&offset=&account_id=&scope=&type="
  //base url + end point + params
  var queryString = baseUrl+endPoint+pointParams;

  var message = queryString;
  var secret = secret;
  var shaObj = new jsSHA("SHA-256", "TEXT");
  shaObj.setHMACKey(secret, "B64");
  shaObj.update(message);
  var signature = shaObj.getHMAC("B64");

  //headers
  var hparams = {
    'method': 'get',
    'headers': {'APIKEY': key,
                'Signature': signature},
    'muteHttpExceptions': true
  };
  //call
  var data = UrlFetchApp.fetch(queryString , hparams).getContentText();
  Logger.log(data)

}