You need to install Perl::Critic
Directs "perlcritic" to only apply Policies with a severity greater than "N".
Severity values are integers ranging from 1 (least severe) to 5 (most severe).
The default is 5.
The "--severity" will usually produce more violations.
Edit the path to your copy of Perl best Pratices in the Settings Dialog.
You can open the ebook via right click -> Open pbp.