html code dosent work

First, you’re on the wrong forums – WordPress.COM support is here:

https://en.forums.wordpress.com/

BUT, it’s not possible to add that kind of code to a WordPress.COM site – it’s not permitted there.

There may be a WordPress.COM widget or shortcode to do that, but you’d need to ask them.

so i need to install a wordpress on a private host to enjoy all those features?

Yep – see the differences here:

https://en.support.wordpress.com/com-vs-org/

thanks WPyogi.

because i know, 2-3 years ago, the code worked perfectly

In that case, I’d suggest asking the WordPress.COM folks about it. These forums only support self-hosted WP.ORG sites.