Where to put PASSPHRASES in Docker (using Redis)?

I'm trying to use https://quirrel.dev/ & want to self-host it myself on https://railway.app (which has a $5 free tier)

I have written the code here → https://github.com/deadcoder0904/quirrel-log

But I don't know where should I put PASSPHRASES as mentioned in the docs?

When I follow the curl step, I get a 404 Page which is Next.js default 404 page.

How do I make sure that my code gets deployed properly? Is my PASSPHRASES property put in the correct place?