Github actions with Railway CLI requires login?

Question

Hey. I'm trying to set up a CI with railway using Github actions. Essentially I'm trying to do the following
- Create a preview url (environment) for a new PR.
- Inject that environment with a some env vars (specifically a DB url).
- Know the preview url location so I can run playwright tests against that URL.

I figured I'd need to use the Railway CLI to do this, but it's been pretty cumbersome. Essentially it fails because I need to login. Looking at the docs, it seems I can use `RAILWAY_TOKEN` or `RAILWAY_API_TOKEN` to bypass login. But it doesn't look like you can use `railway link`? How am I supposed to tell railway to create a new environment for the PR, and then up the result?

I see that railways provides automatic PR environments, but I don't see how I'd be able to provide the vars to it through CI without login and link? Am I missing something.