A private, inaccessible, IANA/IETF-reserved IP address was found for audiobookshelf.drumm.one. Let's Encrypt will always fail HTTP validation for any domain that is pointing to an address that is not routable on the internet. You should either remove this address and replace it with a public one or use the DNS validation method instead.
A and AAAA records found for this domain
audiobookshelf.drumm.one. 0 IN A 192.168.0.247
The IANA public suffix is the TLD of the Registered Domain
The TLD for audiobookshelf.drumm.one is: one
The current status.io status for Let's Encrypt