All travellers flying via Schiphol need to carry a completed health declaration with you when you fly. You can download the form from https://assets.ctfassets.net/biom0eqyyi6b/1ujr8KV2qtylvVTMpEFDDA/063bc2c6100ae1899a0e9d153b356aed/Gezondheidsverklaring_versie2.pdf.
Please complete it by yourself before you leave home. You must be able to show the certificate upon request whether you’re at Schiphol, on the plane or at the destination airport. Keep it in a convenient place with your passport, boarding pass or be prepared to display it on your mobile.