ServiceNow PDF Generation

background.script.js

var UP3PDF = Class.create();  
UP3PDF.prototype = Object.extendsObject(AbstractAjaxProcessor, {  
  
  _document : null,  
  
  createPDF : function(html, table, sys_id, filename) {  
    var pdfDoc = new GeneralPDF.Document(null, null, null, null, null, null);  
    this._document = new GeneralPDF(pdfDoc);  
    this._document.startHTMLParser();  
    this._document.addHTML(html);  
    this._document.stopHTMLParser();  
    this._saveAs(table, sys_id, filename);  
  },  
  
  _saveAs : function (table, sys_id, filename){  
    var att = new GeneralPDF.Attachment();  
    att.setTableName(table);  
    att.setTableId(sys_id);  
    att.setName(filename);  
    att.setType('application/pdf');  
    att.setBody(this._document.get());  
    GeneralPDF.attach(att);  
  },  
  
    type: 'PDF'  
}); 

var p = new UP3PDF();
p.createPDF('<p>Hello World!</p>',  //HTML to convert to PDF  
   'incident',  //Attach PDF to table  
   '85071a1347c12200e0ef563dbb9a71c1', //Attach PDF to record/sys_id  
   'myFile.pdf');  //attachment filename  
  

Hi, I tried your code, though everything seems to be passing on the script include it's not generating the PDF
Getting the below error