NZ releases Covid 19 vaccination passports on Fri 3rd December 2021.
With the power platform you can use PCF (PowerApps Component Framework) to decode the base 32 QR code and validate the data held in the QR Code.
As an MVP I reached out to our community for help for NZ and Rick Wilson created this amazing PCF control. The code is available for reuse as needed - note - its based on the NZ Covid-19 App. Source Code here https://github.com/rwilson504/nzcp-pcf