There is no PIX in Portugal, or places other than Brazil.

What they have there is a Brazilian person receiving payments from another Brazilian person, only through Brazilian accounts, all happening remotely in Brazil(at least for now)

What they have is a payment gateway that integrates the Portuguese and Brazilian payments by doing a transfer at each side.

It's the same thing as buying stuff from China with PIX, but the gateway is more hidden from the Portuguese accounts.

There has been some talk of actually internationalising Pix, but from what I understand, those uses that exist now outside of Brazil are a kludge for the benefit of Brazilian tourists.