They should have said, but I guessing they didn’t because it’s easy and indicates it at the checkpoint. You tell the agent you are declining the biometric identification. Do it as soon as you hand the agent your ID, don’t step in front of the machine, then follow instruction (probably step alongside so they have a clear view of your face).

This Week in Virology talks a bit about this at the 10min mark TWiV 1214: Clinical update with Dr. Daniel Griffin

Episode webpage: https://www.microbe.tv/twiv/twiv-1214/

Media file: https://traffic.libsyn.com/secure/twiv/TWiV1214.mp3?dest-id=25528

Also worth bookmarking the CDC summary… For as long as it’s up. https://www.cdc.gov/bird-flu/situation-summary/index.html