How to upload attachments to a specific task from GAS

English Forum Developers & API
1

I am trying to upload a PDF file to a Asana task as an attachment on Google App Script.
The PDF file is from Gmail attachment and I can get the file on my script like below.

var searchMail = GmailApp.search(condition);
var messeges = GmailApp.getMessagesForThreads(searchMail);

for(var i = 0; i < messeges.length; i++) { 
  for(var j = 0; j < messeges[i].length; j++) { 
    var attach = messeges[i][j].getAttachments();
  }
}

I tried this script to attach the file to a task but the error ‘The request body does not conform to the specification for multipart/form-data encoding.’ returned.
What should I do?

Thank you.

function addAttachmentToAsanaTask(taskId, attachment) {
  const url = `https://app.asana.com/api/1.0/tasks/${taskId}/attachments`;
  const boundary = "-------314159265358979323846";
  const delimiter = "\r\n--" + boundary + "\r\n";
  const close_delim = "\r\n--" + boundary + "--";
  
  let contentType = attachment.getContentType();
  let fileName = attachment.getName();
  let base64Data = Utilities.base64Encode(attachment.getBytes());
  
  let body = delimiter +
    'Content-Type: application/json; charset=UTF-8\r\n\r\n' +
    JSON.stringify({"file": fileName}) +
    delimiter +
    'Content-Type: ' + contentType + '\r\n' +
    'Content-Disposition: attachment; filename="' + fileName + '"\r\n' +
    'Content-Transfer-Encoding: base64\r\n\r\n' +
    base64Data +
    close_delim;
  
  const options = {
    method: "post",
    contentType: "multipart/form-data; boundary=" + boundary,
    payload: body,
    headers: {"Authorization": "Bearer " + token},
    muteHttpExceptions: true
  };
  
  const response = UrlFetchApp.fetch(url, options);
  Logger.log(response.getContentText());
}

addAttachmentToAsanaTask(taskId, attach[0]);