Are you using the openrouter node or the openai node?
As the field organisation id shows, it seems you are using the openai node.
Perhaps you can try to use the new openrouter node instead.
I tested the openai node with the same base url and it also works.
The url is correct and working for me, so the next step would be the API key.
Can you try to recreate a new API key and try again?
If not any of the above, the question is if you are hosting locally or using n8n cloud service.