Schema - Rich Snippets Stars Ratting - Not visible on Google

Hello there,
I am French, sorry for my english
I can't see the stars in the test tools Google
In Consiguration> Schema, I put YES on enable schema.
Should we modify a PHP file after enabling Schema. If so, can you give me the path and name of the file PHP please?
I have this on every page :

<div itemscope = "" itemtype = "http://schema.org/Article" id = "system">

But it lacks that :

<span itemtype = "http://schema.org/AggregateRating" itemscope = "" itemprop = "aggregateRating" class = "extravote-stars">

I thought that enabling Schema in Komento Configuration it would make it all alone but not.
Thank you in advance
Cordially