Sign the dist as the last step before creating the archive. Take care not to modify/regenerate dist meta files or the manifest.

Error: gpg: Signature made Wed 07 Jul 2021 04:13:42 AM JST gpg: using RSA key 4AD7F51220EDBE14 gpg: Can't check signature: No public key ==> BAD/TAMPERED signature detected! <==

Add a META.json to the distribution. Your buildtool should be able to autogenerate it.

Add all modules contained in this distribution to the META.yml field 'provides'. Module::Build or Dist::Zilla::Plugin::MetaProvides do this automatically for you.

This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.