First run perl Makefile.PL and make installdeps to make sure you have 
the required modules

To generate a certificate that matches the config replace the location string
with something relevant for you:

$ openssl req -x509 -nodes -days 365 -newkey rsa:1024 -sha1 -subj   '/C=NO/ST=OS/L=Oslo/CN=osx.iusethis.com' -keyout   myrsakey.pem -out myrsacert.pem

Then go to 

https://www.google.com/accounts/ManageDomains

and add your domain and update the PEM certificate to google

now run script/oauthexample_server.pl to test the application.