Free movement
EU free movement: no work permit needed
As an EU citizen (or Swiss national under the EU–Switzerland agreement) you can generally work here without a work permit. Registration rules for longer stays still apply.
Source: Your Europe (European Union) – Work permits (europa.eu).
What the source says
"As an EU national you generally don't need a work permit to work anywhere in the EU ." … "Under the EU-Switzerland agreement on the free movement of persons, Swiss nationals are free to live and work in the EU." … "Although these countries are not members of the EU, their nationals can work in the EU on the same footing as EU nationals, since they belong to the European Economic Area." (https://employment-social-affairs.ec.europa.eu/policies-and-activities/moving-working-europe/working-another-eu-country/non-eu-nationals_en)