HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

The password is copied to the clipboard when it’s generated anyway.
And if that wasn’t the case, Ctrl+C works in any text input field.

Sorry, I messed up; I was confused because it wasn’t highlighted with the mouse.

By the way, when a Nightmare Dragon drops in the Russian version, a message appears saying something like “send the log to this email address,” but this message doesn’t appear in the English version.