Hello, I'm trying to embed Soundcloud, is this posible?
Thanks.
How to embed soundcloud
Did you ever check this? https://discuss.flarum.org/d/17770-friendsofflarum-formatting
Idk SoundCloud support but it's supports most of popular services.
Yes. Please check out @tolgaaaltas 's post.
Thanks, @tolgaaaltas and @Digital, I will look into it! 
@tolgaaaltas , got an error after activating the extension:
Error booting Flarum: Class FoF\Formatting\Listeners\FormatterConfigurator does not exist
pentarou you should write this error text on extension page. Developer will help you about this.
Will do, thanks!