Adobe Campaign Personalization Button Disabled

We’re unable to get the Adobe Campaign personalization button enabled on our editable AEM email templates that live under the /conf directory.

We've attempted to follow along with the community post here: https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/editable-templates-under-content-campaign/m-p/299591 but it doesn't provide detail about the actual process to make the button work. 

How would we go about making the Coral UI Button available for Adobe Campaign metadata picking on editable templates (under AEM path /conf) ?

Is it possible to make it work with Coral UI 3 Button ?