I chose to take down my production instance of lemmyz do a cp -r of it, update the docker compose file to specify the new version numbers for Lemmy and lemmy-ui plus change the port that the stack exposes and do a docker-compose pull && docker-compose up -d on that stack to check to see if it could all work. Thankfully it did, so I updated the production compose file and tada! I’m on 19.0 safely
I think it’s a relatively recent thing. As the documentation for each of the *arts has a relatively recent minimum version number I think.
Here’s where I went when looking for whisparr, but just replace that with the arr you’re wanting to use and it’ll give you decent steps for getting your database created and migrated into it: https://wiki.servarr.com/whisparr/postgres-setup