This site is a research project demonstrating that web-based verification is problematic. This is a spoof, meant to imitate the official ubirch site. It showcases that the verification, including the blockchain "verification" links (which work!), do virtually nothing to enhance security.
Create your own certificates by changing the values in the URL. It will always blink green. You could plug the QR code below into any "fake" covid certificate..
Q: Do you have a better idea?
Use paper. Ffs.
Also, the labs already sign the test results. There's your trust anchor. Put the signature in the QR code. Use app to verify signature. Drop all the blockchain crap.
Contact the team at firstname.lastname@example.org