ECG is not available in my country

Hi guys, I need some help, I can’t use ECG.

My iPhone and Apple Watch were bought in US, model final LL/A.

Currently I am in Brazil, but I don’t think there is something like georeferencing.

I already tried changing regions, language, force reboot, on both devices.

I don’t know what to do anymore.

I have ECG app on my Apple Watch, and it is available on Health app, but when I try to use it, after putting my birthday, it says that is not available in my country.

Any ideas?