apple watch cellular support in Portugal

This is a user-to-user technical support forum. The volunteers here do not have any privileged information.

It takes more than eSIM support. The carrier has to be able to share the iPhone phone number with the Apple Watch. Not all carriers are able to do that (physically, or contractually), or they are not interested in do it. You will to ask your carriers.

That’s a question for your local cell carriers. They are the ones that need to support it. Apple has no real way to force them to support it.