We are trying to host a private mirror of some repositories. The ubuntu repositories appear to be working fine however we have also added a repository from ppa launchpad. Whilst apt-mirror seems to be doing the trick the problem is that when apt (client) is trying to download the repo it complains there's no PUBKEY
W: GPG error: http://apt.mydomain.com/ondrej/php/ubuntu bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4F4EA0AAE5267A6C
How can I provide the key through the repo?
We're using apt-mirror and serve via nginx running on Ubuntu 18.04 server.