you may need to check your server's DNS configuration or make sure that the hostname "lemmy-ui" is correctly defined and reachable in your network. It looks like it's expecting the lemmy-ui to be on the .57 machine. If you are expecting it on the .62 then something is misconfigured in the script.
It just looks like it can't find that host.
Sorry I can't be more help. I don't run a Lemmy instance and I'm not familiar with the ansible config you are using.