How to integrate commento.io to your blog

Hi there, if u choose cms like ghost, wherein no comments in core u think, what comments system i need?
First thing that comes to mind - Disqus, most popular, most functional comment system for now. But, what's the price on free plan? This price so expensive. first of all, loading your articles will slow down, slow down a lot, second - follows from the first, disqus load so many javascript to track and spy you, they sell information about u to 3rd parties, third - ugly ad on "free plan".
I spent about a day to reading something about comments system and choose - commento.io.
So, let's begin. Firstly u must registration on commento.io. After registration add your domain to service. Second u can use commento like self-hosted solution, but i use their cloud server, just copy-paste this script in your site footer.

<script defer
  src="https://cdn.commento.io/js/commento.js">
</script>

And then paste this div in your post template.

<div id="commento"></div>

So simple, and u have comments system on your website, standard css u can overwrite with data-css-override attribute in tag script, for example, how i do that.

<script defer src="https://cdn.commento.io/js/commento.js" data-css-override="https://alxy.ru/assets/scss/theme/commento.css"></script>

Alexandr