Ask the owner of the distribution (the one who released it first, or the one who is designated in x_authority) to give you a (co-)maintainer's permission.

Split the distribution, or fix the version numbers to make them consistent (use the highest version number to avoid version downgrade).

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.

Add CONTRIBUTING(.pod|md). See https://docs.github.com/en/communities/setting-up-your-project-for-healthy-contributions/setting-guidelines-for-repository-contributors.