An error occurred while trying to export OpenPGP certificates.
Server indicated a failure gpg: keyserver send failed: Server indicated a failure
It is because the SKS PGP Keyserver is being abandoned due to peoples abuse of known public keys on the server. I stumbled on this article when I tried looking for other keyserver lookup as alternative as I was also following the same tutorial. But still, even without uploading it to a keyserver, you can still verify the pgp signature of an application and encrypt/ decrypt a message.
The Death of SKS PGP Keyservers, and How First Look Media is Handling It
The SKS keyserver network is dying. This has been a long time coming. The nail in SKS’s coffin came in late June when someone abused important public keys that people rely on.