This is such a better design than whatever the UK is trying to do[1]. Why make a 3rd party app a requirement for this? I will never install such an app, especially one not made by the government itself.
[1]: https://www.dailystar.co.uk/news/latest-news/digital-id-upda...
Looks like the criteria were 1. No cost to the government/taxpayer. 2. Minimal work for the civil service.