% cat /usr/local/etc/pkg/repos/base.conf 
# FreeBSD pkgbase repo

FreeBSD-base: {
  url: "https://alpha.pkgbase.live/current/${ABI}/latest",
  signature_type: "pubkey",
  pubkey: "/usr/share/keys/pkg/trusted/alpha.pkgbase.live.pub",
  enabled: yes
}
% sudo pkg update -r FreeBSD-base
grahamperrin's password:
Updating FreeBSD-base repository catalogue...
Fetching meta.conf: 100%    163 B   0.2kB/s    00:01    
Fetching packagesite.pkg: 100%   33 KiB  33.5kB/s    00:01    
pkg: -----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----
: rsa signature verification failure
pkg: Invalid signature, removing repository.
Unable to update repository FreeBSD-base
Error updating repositories!
%