It doesn't work in New Zealand. Operators have not deployed the infrastructure needed for it.
https://www.geekzone.co.nz/forums.asp?forumid=97&topicid=275...
Here is some interesting comment from a telco staff https://www.geekzone.co.nz/forums.asp?forumid=76&topicid=315...
What I meant is, interoperability between iOS RCS and Android RCS won't work until telcos deploy their own servers and Google fallback to those.
The iOS 18 RCS client provisioned in the US, UK, Spain, Germany, ... connects to Jibe and can send messages to Android devices running Google Messages.