You need the VCP (virtual com port) drivers. Scroll down just a little bit on the center of the page I linked and you should see a chart of operating systems and processor architectures. Pick the one that matches your system. If you’re running Windows and your computer isn’t terribly old, you probably have “x64 (64-bit)”. If you’re not sure, instructions for checking are here: https://support.microsoft.com/en-us/windows/32-bit-and-64-bit-windows-frequently-asked-questions-c6ca9541-8dce-4d48-0415-94a3faa2e13d
I think many macs have the FTDI drivers pre-installed.