How can the meeting button (for Lync integration) be made availble on the outlook 2011?

Hi

I have the Lync already installed but I´m incapable of seeing the button to create the online meeting in the Outlook

I have found many post to solve  this question but for the Windows version not for Mac.

I think I have to make available this button through the option activate COM complement in one of the Outlook menus, But I don't know where this options is (in which menu)

Could you help me?

Thanks in advance

Ana