I also bought it.

I had to download and install the UJAM setup, then the VG-SILK_osx_1418.pkg as well as create an account.

I had to use the UJAM package in order to install the VST. Then opened the VST in one of my DAWs (Reaper) and I was promted to authorise it by entering my email and password. Works fine in Studio One as well. A very tedious process.