Live-reloading with Browser Sync not working

[diego-1881]

This is my gulp.js configuration file.

When I save any of my .scss files the browser doesn't reload, any idea were is the problem with my code?

var gulp = require('gulp');
var sass = require('gulp-sass');
var browserSync = require('browser-sync').create();
gulp.task('browserSync', function() {
  browserSync.init({
    server: {
      baseDir: 'app'
    },
  })
});
gulp.task('sass', function() {
  return gulp.src('app/css/*.scss') // Gets all files ending with .scss in app/scss
    .pipe(sass())
    .pipe(gulp.dest('app/css'))
    .pipe(browserSync.reload({
      stream: true
    }))
});
gulp.task('watch', gulp.series('browserSync', 'sass'), function (){
  gulp.watch('app/css/*.scss', gulp.series('sass'));
  // Other watchers
});