Comment by vetinari

For example, see https://www.slovensko.sk/sk/na-stiahnutie

It is the portal for Slovak republic. You are supposed to have your national ID card, which is a smart card. To use it, you need a smartcard reader and an application, which basically listens on localhost and is kind of a intermediate between your browser, the pages than need authentication and the department of state, which handles IAM.

That application runs on Windows, Mac and Debian (9,10)/Ubuntu (18.04,20.04)/Mint (19.20) (it is not open source). Other distributions are not supported, forget ChromeOS.

It is quite onerous. You have to enter your PIN for smartcard about four times, before you see the content of the inbox.