Works with this code, but still get fn undefined error

I had issues every step of the way. Needed to add node support to app.js and made changes to index.js too. I don't know why replacing the callback way of doing it with a promise way worked, but with the following code getting the cat pic, annotating and printing on 'p' press all work.

However, still getting error messages in the console, similar to https://github.com/maxogden/elementary-electron/issues/32

Tracked them to here:
https://github.com/visionmedia/superagent/issues/676
https://github.com/visionmedia/superagent/issues/714

but I couldn't figure out where it's being included from to test if upgrading the version fixes it or such.

app.js

var electron = require('electron');

electron.app.on('ready', function () {
    var mainWindow = new electron.BrowserWindow({
        width: 600,
        height: 800,
        webPreferences: {
            nodeIntegration: true
        }});
    mainWindow.loadURL('file://' + __dirname + '/index.html');
})

index.js

// Get cat pic src
var catpicture = require('cat-picture');
var src = catpicture.src;
catpicture.remove();

// Get annotation
var image = require('lightning-image-poly');
var viz = new image('#visualization', null, [src], {hullAlgorithm: 'convex'});

// Save pdf
var fs = require('fs');
var remote = require('electron').remote;

function save () {

    remote.getCurrentWebContents().printToPDF({portrait: true})
        .then( data => {
            fs.writeFile('annotation.pdf', data, function (err) {
                if (err) {
                    alert('error generating pdf! ' + err.message);
                } else {
                    alert('pdf saved!');
                }
            })
        })
        .catch (err => {
            console.log('test');
        })
}

window.addEventListener('keydown', function (e) {
    if (e.keyCode == 80) save()
})

Start by reviewing app.js and index.js, then trace which dependency brings superagent into the application. Compare the reported console errors with superagent issues #676 and #714 and investigate the dependency version. Done means identifying the source of the errors and confirming whether an available dependency update removes them without breaking the working cat-picture, annotation, and PDF behavior.