ERROR: Buffer Message to string ascii contains invalid characters

[SimeonDominiq]

Hi @zemuldo ,
Thank you for this wonderful package.

I have this sample data format below:

const data = {
  0: "0800",
  3: "9C0000",
  7: currentDateTime.format("MMDDHHmmss"),
  11: "233456",
  12: currentDateTime.format("HHmmss"),
  13: currentDateTime.format("MMDD"),
  41: "5TSAD61",
};

const customFormats = {
  3: {
    ContentType: "an",
    Label: "Processing code",
    LenType: "fixed",
    MaxLen: 6,
  },
};

const iso8583 = new Iso8583(data, customFormats);
const bufferMsg = iso8583.getBufferMessage();

console.log(formattedData.toString("ascii"))

//Output - which contains these characters "<", '"'
<0800"89A0000012911091923345611091901292PSTAD61

//Expected Output
08009A0000012911135623345611135601292PSTAD61

Also, in the sample response that I got from the request, I am trying to get the response to JSON but I keep getting this error below:
// sample response:
01520810023800000280080001291120582334561120580129002PSTAD61347687EAB94DD02C889650483EFF57FE1F609246517A2D82CBA3DC9DD3AB1C6ECBA3DC9DD3AB1C6ECBA3DC9DD3AB1C6E

  const iso8583 = new Iso8583(Buffer.from(data, "utf-8"));
  console.log(iso8583.getIsoJSON(), "iso8583", data);

//Error
{ error: 'expecting buffer but got undefined' }

I would appreciate your kind help in resolving these issues that I have while using the package.

Thank you for your time.