Why does Youtube-mp3-downloader give the unexpected token error?

I try to understand the library Youtube-mp3-downloader but I constantly run into the error SyntaxError: Unexpected token

How do I get the library to work?

Ffmpeg is located in the same folder as the executable file.

Core.js

console.clear()
var Downloader = require("./loader");
var dl = new Downloader();
var i = 0;
dl.getMP3({ videoId: "Vhd6Kc4TZls", name: "Cold Funk - Funkorama.mp3" }, function (err, res) {
    i++;
    if (err)
        throw err;
    else {
        console.log("Song " + i + " was downloaded: " + res.file);
    }
});

Loader.js

var YoutubeMp3Downloader = require("youtube-mp3-downloader");
var Downloader = function () {
    var self = this;
    //Configure YoutubeMp3Downloader with your settings
    self.YD = new YoutubeMp3Downloader({
        "ffmpegPath": "./ffmpeg.exe",        // FFmpeg binary location
        "outputPath": "./data",    // Output file location (default: the home directory)
        "youtubeVideoQuality": "highestaudio",  // Desired video quality (default: highestaudio)
        "queueParallelism": 2,                  // Download parallelism (default: 1)
        "progressTimeout": 2000                 // Interval in ms for the progress reports (default: 1000)
    });
    self.callbacks = {};
    self.YD.on("finished", function (error, data) {
        if (self.callbacks[data.videoId]) {
            self.callbacks[data.videoId](error, data);
        } else {
            console.log("Error: No callback for videoId!");
        }
    });
    self.YD.on("error", function (error, data) {
        console.error(error + " on videoId " + data.videoId);
        if (self.callbacks[data.videoId]) {
            self.callbacks[data.videoId](error, data);
        } else {
            console.log("Error: No callback for videoId!");
        }
    });
};

Downloader.prototype.getMP3 = function (track, callback) {
    var self = this;
    // Register callback
    self.callbacks[track.videoId] = callback;
    // Trigger download
    self.YD.download(track.videoId, track.name);
};
module.exports = Downloader;