To extend your channels.scm
file, adapt accordingly:
(append (list (channel
(name 'foundation)
(url "https://github.com/Foundation-Devices/guix-foundation")
(introduction
(make-channel-introduction
"3a3047c62efa68335f9c371d6de71375e042e5f2"
(openpgp-fingerprint
"9D54 3ADF 6E90 348C C606 90A9 6279 AEC2 0A95 24EC")))))
%default-channels)