For the past week or so, whenever I try to launch vTuber Kit I get a popup that it's being blocked by Windows Smart App Control. It appears to be something to do with the app not having a valid signature? I ended up getting around this by disabling Smart App Control. Not sure if there's a way to fix this, but I figured I'd post this in case anyone else is having this issue.

Go to more then you can press run anyway

You can do what owenj525 said. You can also try running the app through the Itchio Desktop App, I think that bypasses the windows check.