How to use the browser-sync.notify function in browser-sync

.on('error', function(err){
      browserSync.notify("SASS error");

      console.error(err.message);

      // Save the error to index.html, with a simple HTML wrapper
      // so browserSync can inject itself in.
      fs.writeFileSync('serve/index.html', "<pre>" + err.message + "</pre>");

      // No need to continue processing.
      this.emit('end');
    })
    // AutoPrefix your CSS so it works between browsers

gulp.task('scripts', function(callback) {

  browsersync.notify('Compiling JavaScript');

  var bundleQueue = config.bundleConfigs.length;

  var browserifyThis = function(bundleConfig) {

    var bundler = browserify({
      // Required watchify args
      cache: {}, packageCache: {}, fullPaths: false,
      // Specify the entry point of your app
      entries: bundleConfig.entries,
      // Add file extentions to make optional in your requires
      extensions: config.extensions,
      // Enable source maps!
      debug: config.debug
    });

export const jekyll = done => {
    browser.notify('Compiling Jekyll')

    let jekyllOptions

    if (isProduction) {
        process.env.JEKYLL_ENV = 'production'
        jekyllOptions = 'jekyll build --lsi'
    } else {
        process.env.JEKYLL_ENV = 'development'
        jekyllOptions = 'jekyll build --config _config.yml,_config.dev.yml --incremental --drafts --future'
    }

    const jekyll = cp.execFile('bundle', ['exec', jekyllOptions], { stdio: 'inherit' })

    const jekyllLogger = buffer => {
        buffer.toString()
            .split(/\n/)

function errorHandler(error) {
  browserSync.notify(error.message, 3000);
  log('[Error!] ' + error.toString());
  if (process.argv.indexOf('--fail') !== -1) {
    process.exit(1);
  }
}

setTimeout(function() {
          browserSync.notify('reloading now ...');
          browserSync.reload({stream: false});
        }, config.browserReloadDelay);
      })

gulp.task('sass', function () {
    browserSync.notify('<span style="color: grey">Running:</span> Sass compiling');
    return gulp.src(settings.sass + '/**/*.scss')
      .pipe($.sass(eyeglass.sassOptions()).on("error", $.sass.logError))
      .pipe($.autoprefixer('last 2 versions', '&gt; 1%'))
      .pipe(gulp.dest(settings.css))
      .pipe(gulp.dest(settings.assets))
      .pipe(browserSync.reload({stream: true}));
  });

setTimeout(function() {
                browserSync.notify('reloading now ...');
                browserSync.reload({stream: false});
            }, config.browserReloadDelay);
        })

gulp.task('jekyll-dev', function (cb) {
    browserSync.notify('<span style="color: grey">Running:</span> $ jekyll build');
    return cp.spawn('bundle', ['exec', 'jekyll', 'build', '--config=_config.yml,_config.dev.yml'], {stdio: 'inherit'})
      .on('close', cb);
  });

gulp.task('jekyll-build', function (done) {
    browserSync.notify(messages.jekyllBuild);
    return cp.spawn( jekyll , ['build'], {stdio: 'inherit'})
        .on('close', done);
});

gulp.task( "jekyll-build", done =>  {
    browserSync.notify( messages.jekyllBuild );
    return cp.spawn( jekyll, [ "build" ], { stdio: "inherit" } )
        .on( "close", done );
} );