There is no "official" download site because it is community-developed (often attributed to "Chingachguk & Denger2k"). 1. Enable Test Mode
Most virtual USB multikeys come with software that allows you to configure the device. This could involve setting up which virtual devices to emulate.
If possible:
To download the virtual USB multikey key 64-bit driver, follow these steps:
Version 21.x of the driver was accidentally signed by a third-party certificate.