https://www.freebsd.org/doc/en/articles/committers-guide/pgpkeys.html

[Kurt Lidl]

Greetings,

In this document, it suggests running "gpg --gen-key".

As of today's version of gnupgp:

lidl at hydra-129: gpg --version
gpg (GnuPG) 2.1.8
libgcrypt 1.6.3

The dialog that is presented doesn't give the option for
specifying keylength, expiration date, etc.

To get the dialog that is shown in the web page, you must
issue: "gpg --full-gen-key"

-Kurt