Just wanted to mention that Virtualmin backups wouldn’t work until I installed
libdigest-hmac-perl. (I was getting errors like, “The Perl module Digest::HMAC_SHA1 needed to communicate with Amazon's S3 service is not installed”.)
apt install libxml-simple-perl
apt install libdigest-hmac-perl
I also tried installing
libwww-perl, and it seemed to be installed already.
apt install libwww-perl