There is a current discussion related to your question that you might find helpful: [webmasterworld.com...]

That discussion is not about FB but about editing your Google Profile so it may help.

Thank you so much, i've seen it but we already have our profile generated, so it's a diferent question.

I ran into something similar and the schema alone did not force it to appear. Google seems to pick which social profiles to show based on confidence and consistency across sources. Make sure the Facebook page links back to the same site in its about section and that the brand name matches exactly. Also check that the FB URL in your schema is the clean canonical page URL, not one with parameters or redirects. Sometimes it just takes time for Google to reconnect the entity.