@giacomosilli there is no random ordering available through handlebars or the API as it would not work how you expect due to multiple levels of caching - you’d likely end up with the same 2 posts shown consistently until something was changed which caused the cache to be rebuilt.
You could do something client-side using the Content API if you fetch a list of IDs for posts which match your filter and then randomly selecting a couple of those IDs to do full fetches.