The COVID digital certificate is going into effect across the European Union, meant to facilitate travel and otherwise ease life for people who have tested negative, have recuperated from COVID and have proof of it, or have been vaccinated — including only with one dose for the two-dose vaccines, although that’s not enough for most travel, including to leave the Lisbon Metropolitan Area when it’s in lockdown as it has been during the past two weekends.
If you qualify for one of the above-mentioned reasons, and if you have a numereo de utente from Portugal’s national health services (Serviço Nacional de Saúde), you can sign up for the digital certificate here: https://www.sns24.gov.pt/certificado-digital-covid.
Related: Vaccine Signups in Portugal Opened to Those 33 and Older
Related: Illegal Immigrants in Portugal, Those Without SNS Number Can Apply for COVID Vaccine.