You need to define property settings for your XHtmlProperties that includes this button. By default it should be enabled but if you have a customized toolbar you might not get it. Go in to admin mode, find the settings for XHTML property type and change the default settings or change the settings for each property for your page types if you have custom property settings per property. If you're using Page Type Builder I think that version 2 supports defining property settings directly in code.
I need to add a Visitor Group Personalization button in the Tiny MCE Editor or in the Editor Control. How can i add that personalization button in the Editor?