There is a clinic from Vitolus (Tel +49 899 0421 2661) inside car park P7 that opens from 8:00 am to 8:00 pm, while in Departures Hall 1, there is a test centre from EcoCare (Tel +49 211 3878 9573) available from 5:00 am to 5:00 pm.
At both clinics, you can take a PCR test or an antigens test for COVID-19.