Cubase 12 - SpectraLayers not present?

Just updated to Cubase 12 and SpetraLayers is not available. Projects that used SpectraLayers brings the following error: “The project file contains ‘SpectraLayers’ data which is not supported by this program version. The data is ignored”.

Where can I add SpectraLayers as an extension?

I now know what happened. I thought that installing SpectraLayers 8 would make the extension available in Cubase 12, I uninstalled version 7. After reinstalling version 7, I have the extension again, but it has a banner saying that version 8 is available, but I already installed version 8 on my system.

Version 8 is not available as an extension in Cubase 12?