Widget passing variables

I have created a widget to print on a local printer using qz

https://qz.io/

I can get the sample to print but I can't get the passed data to print it keeps saying undefined. How do I get the printData variable down to the data section?
this.onPrint = function(printData){
    
   qz.websocket.connect().then(function() { 
       return qz.printers.find("Pin Printer")               // Pass the printer name into the next Promise
}).then(function(printer) {
  var config = qz.configs.create(printer);       // Create a default config for the found printer
  var data = ['^XA^FO50,50^ADN,36,20^FDRAW ZPL EXAMPLE^FS^XZ'];   // Raw ZPL
  return qz.print(config, data);
}).catch(function(e) { console.error(e); });
 
}

Thanks,
Tim Larson