Thank you for the advice, I appreciate it!
It took some hunting around to find (for some reason when I open the plugin store there only seem to be a handful of plugins available, not including sketchucation tools) but after searching I found a link to it from a news item and then was able to download it and then when I tried to use the extension I again got the error message but the "help with licensing" button now brought me to a page where I could activate my license by searching up my copy of it, and now the extension works.