Free movement
EEA free movement: no work permit needed
Free movement of workers applies in general terms to Iceland, Liechtenstein and Norway as part of the European Economic Area, so EU and EEA citizens can generally work without a work permit.
Source: European Commission – Free movement of EU nationals (employment-social-affairs.ec.europa.eu).
What the source says
"work there without needing a work permit" … "Free movement of workers also applies, in general terms, to the countries in the European Economic Area (Iceland, Liechtenstein and Norway)."