PKA records

[R. Martinho Fernandes]

I can't seem to find any up-to-date documentation on how to deploy DNS
PKA records for use with `auto-key-locate`. I tried `gpg
--export-options export-pka --export` and pasted those records directly
in DNS, and yet when I use `--auto-key-locate pka`, I get:

     error retrieving 'rmf at rmf.io' via PKA: Not found

The old PKA records (TXT "v=pka1; ...") had a URI, but I can see that
the new one that I exported only includes the key fingerprint, so it
obviously cannot be used for retrieval alone. What am I missing?