Here ( http://www.gpg4win.org/doc/en/gpg4win-compendium_16.html ) I have read this:
So how does the authentication process work?
In Kleopatra, select an OpenPGP certificate that you think is real and
would like to authenticate. In the menu, select: “Certificates →
I want to do it with the key of the Tailing signature key from here: https://tails.boum.org/download/index.en.html#verify
But I don’t see the “Certificates → Authenticate certificates…” menu item.
Is the documentation is not corresponding the current version of Kleopatra?