1821 Portugal 400 Reis Coin is it real /

The thing which is confusing me is the weight it's 41.73 grams
Is this real and what is it please is it brazil or portugal ?

The corresponding coin in the Numista catalog is

https://en.numista.com/catalogue/pieces24467.html

It looks like an 80 Reis (corresponding to the Roman numerals LXXX) under Joao VI of Brazil, KM #342. However, you are correct that the weight of your coin is much greater than the listed weight of 28.69 g, which is suspicious. I'm not an expert in this type of coin, so will let others comment on its authenticity.

Diameter? Thickness? Looks much thicker than 1.5 mm.

It's a contemporary counterfeit.

They were common in some brazilian provinces in the 1820's. So common that in some places they were more than half of the circulating coins, like in the Bahia province (by the way the mintmark B is for Bahia).

Please check this: https://en.numista.com/forum/topic70994.html (from when I got my first of these).
https://brasilmoedas.com.br/artigos/#moedas-falsas (info text in portuguese)