ARIA RadOnc STructure Sets as a Scalar Volume - won't load

Hello!
I am trying to load in Radiation dose map into slicer, but I am getting the following error message: ARIA RadOnc STructure Sets as a Scalar Volume - won’t load
Operating system:Windows 10
Slicer version: 4.10.1

You need to install SlicerRT extension to be able to load DICOM RTSTRUCT information objects.