I don’t want upgrade my acount right now. I just want make some tests and see if things works as I expect then I’ll update my account. Because when I try run the preview nothing happens.
You cannot preview custom elements on a live site without upgrading. You might be able to test them in Preview Mode. You can also become a Wix Developer, and you will be able to create a free premium website to test your apps. This is the best way.