Ibzh I don't see the link between that Lameric thing and what you're trying to achieve. This looks like advertisement.
You mean you want to retrieve this information via the Flarum API ?
The totals are not available via the public API. And not really via any private API either unfortunately...
The totals are loaded by the Statistics extension in the admin panel, but it doesn't expose any API endpoint, the data is loaded inside the HTML page as JSON payload. So not really reusable.
The easiest would be for you to register a new API route, maybe check that the user is admin, then return the model count for each of the resources. Let me know if you need help with that.