Problem at downloading the purchased driver

I have turned my ASUS Chromebook Vibe CX34 Flip into Windows 11, and after that I have tried to install de CoolStar SOF Audio (Intel/12S) driver by paying on Patreon and buying the driver on the coolstar page. But when I’m going to download it, the page asks me for an unsigned license file, and I don’t understand what that refers to. Could someone help me?
PD: in the driver’s description, it says that you have to see the README for more info, but I can’t find this file anywhere.