How to upload and convert XLSX file to JSON using ember.js

I am trying to allow the user to upload an XLSX file to be converted to a JSON or CSV file to be parsed through on the back-end. I am using node.js, and tried several packages including the read-excel-file (https://github.com/catamphetamine/read-excel-file/blob/master/README.md)

readXlsxFile(file).then(function(data) {
let jsondata = JSON.parse(data);
-do something with jsondata-
});