That’s not yet possible but a future release will support OpenRouter and also OpenAI-compatible endpoints (but the integration is less powerful in this case as it’s basically the lowest common denominator).
PS: These kind of services are cropping up all over the place at a dizzying pace. We logically won’t be pursuing integration of all of these (no matter how they all hype themselves as ‘the GAME CHANGER!!’) OpenRouter has been most often requested and was in more of a “first to market” situation than others for the AI community.
This is akin to the sync situation. Dropbox was first to market, had a ton of traction, in and out of tech circles, so logically was the most asked for.
The OpenAI compatible option requires the API endpoint /v1/models/ to load the list of models and /v1/chat/completions for chat completions and that’s the URL that can be entered in Settings > AI > Chat. It’s not a URL to directly access an unknown API & model with unknown features.