I also have the Microsoft Sculpt keyboard and I DO have the USB connector which I am connecting to my MacBook Pro using a Belkin 3 port USB-C adaptor however, the Mac was not recognizing the USB connector. After several purchases, I discovered that it must be about the type of USB-A port needed, not a Mac issue USB in that the USB-A port in the Belkin 3 port USB-C adaptor does not support the keyboard, but that the identical looking Mac 3 port USC-C adaptor does work. Also the blue **** ports the Belkin 11-in-1 Multipot Dock (which I believe are USB-A 3.0) work as well. Just thought I'd share because for anyone else troubleshooting this since this is my favorite keyboard out and I wasn't finding much information online about what the issue might be. It just said 'it should work'.
Hope this helps someone else.