CCleaner 1.17.603 Wipe Freespace Not Working

CCleaner for Windows CCleaner Windows Help Requests
1

I am running CCleaner Professional 1.17.603 on a Mac OSX 10.15.4. I am attempting to erase Free Space on the Macintosh HD. However, when I click on Erase Free Space, nothing happens.

I would appreciate any advice please.