Digital service providers who are not established in the European Union but offer services to EU operators of essential services must designate a representative in the Union (Directive (EU) 2016/1148, Article 18(2)). For an unofficial version of the Law 4577/2018, use this link: https://www.kodiko.gr/nomothesia/document/474449/nomos-4577-2018Under Article 27 of the GDPR, representatives of controllers or processors not established in the EU must be established in one of the Member States.