make sure your .env file is set up properly: DB_HOST=[ipv6_address] . Since the domain is private, confirm that mySQL is listening on correct ip/interface bind-address = :: . One thing you should also consider the user you're using has access to MySQL from host.

Where can I access a shell in Railway? I want to ping my private domain from within the private environment to check if it's reachable inside the network. I have access to my MySQL database, and the domain shown in Railway's environment variables appears to be correct. I was previously using a public domain to connect Laravel to MySQL, but since both services are in the same project and environment, I want to switch to the private domain to reduce costs on the database connection