This should be increased to at least version 2.0.0 of certbot, because the zope interfaces got removed in #25 (see the second comment in that issue).
Without the interfaces this plugin is not working with older versions of certbot. For example, Debian 11 is shipping version 1.12.0 of certbot, which will produce this error message:
PluginEntryPoint#dns-inwx does not provide IPluginFactory, skipping
PluginEntryPoint#certbot-dns-inwx:dns-inwx does not provide IPluginFactory, skipping
The setup script still requires a certbot version >= 0.15: https://github.com/oGGy990/certbot-dns-inwx/blob/c3952fd8179690a679c69c61149206f363c23bce/setup.py#L8
This should be increased to at least version 2.0.0 of certbot, because the zope interfaces got removed in #25 (see the second comment in that issue).
Without the interfaces this plugin is not working with older versions of certbot. For example, Debian 11 is shipping version 1.12.0 of certbot, which will produce this error message: