How to enable Related topics?

[JammyDodger]

It is indeed available.

It’s part of the AI plugin. You can find out some info on how to set that up if you’re self hosted here:

Discourse AI - Self-Hosted Guide

This is a guide aimed at running your own instances of the services that power Discourse AI modules. Introduction If you want to use Discourse AI on your self-hosted instance, you may need to also run the companion services for the modules that you want to enable. Each module has one or more needed companion services, and those services use more CPU / GPU / disk space than Discourse itself, so keep in mind that this is not recommended for people unfamiliar with Linux server administration an…

And another guide for the Embeddings module itself here:

Discourse AI - Embeddings

This topic covers the configuration of the Embeddings module of the Official Discourse AI Plugin plugin. Embeddings is now pre-configured for all customers on our hosting. We provide the embeddings required through open-source models, meaning you can simply enable the AI features that depend on it. Feature set The Embeddings modules can automatically generate embeddings of every new post in your Discourse instance. Those are used by our semantic features, like semantic suggested topic…