I installed the plugin on the server, activated it from admin console but there is no way to get it work. 

I cannot write an email register step to activate the license as I Filemaker Pro does not provide me the 360 functions in the script/functions editor. 

How can I bring the plugin to life?

To use the functions with FileMaker Pro Advanced on your local machine, you also need to install the plugin on your local machine. The server install only allows the FileMaker Server Script Engine to use the functions. And there is a separate location if you are using the plugins with Custom Web Publishing.

Installing the plugin on FMS does not give you access to it in the FileMaker Pro script workspace regardless if the file you are accessing is hosted or not. This is the case for any FileMaker plugin. Installing on the server only makes the plugin available for scheduled scripts or scripts executed with the Perform Script on Server (PSOS) script step. This means that either your scripts will need to be executed as a schedule or with the PSOS script step unless you want to install the plugin on all user machines.  As Josh said, in order to write the scripts, you will need to install the plugin in FileMaker Pro to have access to the functions. See this page for installation locations.