To prove your vaccination and testing status, you must show the Al Hosn app (with green status) or the official health app from your country of residence. If you’d like to use the Al Hosn app, you must: Register at ICA.gov.ae before you fly; Collect a UID number at the immigration desk in Abu Dhabi; Register using your UID number on the Al …
Link: https://www.etihad.com/en-us/travel-updates/abu-dhabi-travel-information