Apt repo no longer signed

Chef Infra (archive)
1

I started receiving this error today when running "apt-get update" on our chef server:

E: The repository 'https://packages.chef.io/repos/apt/stable focal Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

This is on an Ubuntu 20.04 server. The apt repo was added by following the steps here under Debian/Ubuntu: Chef Software Packages

2

Me and another person were chatting on Slack about this same issue. He was using the apt repo and I'm using the YUM repo.

3

This should be working again.