Deploy Action Cable & Redis to production

I'm currently integrating Stimulus Reflex and Cable Ready in my application and want to deploy it to my production server. The guide here on how to deploy ActionCable to production seems very outdated, so some questions:

I found different tuturials on this topic, but most of them for Rails 4/5.
Regarding the cable.yml configuration file: If I install redis on my webserver, does the production url have to point to localhost or to my domain (url: redis://localhost:6379/1 or url: redis://redis.mydomain.com:6379/1)?