Magento - 在Out-Of-Stock产品上显示Belvg Color Swatch属性

I need to know how to display attributes for products when they become Out-Of-Stock. Attributes like:

 - colour

Currently I use Belvg Color Swatch Pro extension and i'm not able to activate this setting. I found on their presentation page for this plugin "Swatches of out-of-stock products can be set to be displayed.". But in Magento extension panel I can't see this feature.

Does anyone have an idea on how to solve this? Thank you

Did you tried to contact Belvg Support?