This is a general example of using use Net::Facebook::Oauth2; For a better understanding I recommend you to look at the Catalyst example Don't worry if you are not familiar with catalyst, I tried to make it as simple as I can with no complication, plus Catalyst is awsome :)
To install Net::Facebook::Oauth2, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Net::Facebook::Oauth2
CPAN shell
perl -MCPAN -e shell install Net::Facebook::Oauth2
For more information on module installation, please visit the detailed CPAN module installation guide.