The mobile authentication for the NHI express app didn’t work with ARC numbers (same technical issue as this year’s tax filing system).
Good news: We’ve fixed it with the TWCA and telecom operators; both new- and old- style ARC numbers will be supported once the platform launches.
Aside: The “not eligible” message is because the platform is currently in closed beta and does not translate to vaccine eligibility. If you are receiving second jab of AZ, please check with the original hospital where the first jab was given to you.