There’s the old trick of setting your computer language to be different from the Siri language. I get the following error message when I open Siri in Settings:
> Apple Intelligence requires that Mac and Siri are set to the same language. Currently your Mac is set to English (United States) and Siri is set to English (Canada).
I think at one point they may have removed this limitation but then they reintroduced it in macOS 27.0.