Slicer-4.13 uses ITK5 and the maintainer of the extension has not updated his code yet to make it compatible with this ITK version - see this bug report:
You can write a comment to this bug report and see if we get any response. You can fix the code yourself, too (you can ask help on the ITK forum, they are always very responsive and could tell you what needs to be changed. If things work on your computer then we can fork the repository and make those fixes, even if we don’t hear from the original maintainer.