Onzi writes and publishes articles to your WordPress site. With this plugin installed, an article that exists in several languages arrives as one post per language, each filed under the right language and linked to its original, exactly as if you had created the translations by hand in Polylang or WPML. Your language switcher, hreflang tags and per-language categories all work as usual.
You only need it when your site uses the free version of Polylang or WPML. Polylang Pro works with Onzi out of the box, and a single-language site needs nothing at all.
The plugin has no settings and no screens of its own. It does not send anything to Onzi; Onzi talks to your site the same way the WordPress app does, using the application password you created when connecting.
For developers
WordPress core has no notion of a translation. Polylang Pro exposes two REST API fields on posts and categories, lang and translations, that say which language a post is in and which posts are its translations. Free Polylang and WPML keep the same information but do not expose it over the REST API. This plugin registers those two fields, with the same semantics as Polylang Pro, on top of whichever plugin you run, and answers one read-only route (GET /wp-json/onzi/v1/site) that lists the configured languages. Any client that speaks Polylang Pro’s REST contract works against it.