In addition just to let you know. You don't use both cables they are both for controlling the RGB. Use the one with the RGB header if you want to control the RGB with your motherboard software.
Use the USB that connects to a USB header if you want to control with the Cooler Master RGB software, CM makes the cooler for AMD.
I don't know where to buy the USB cable.
The usb software if you end up with one of those cables can be had here:
https://landing.coolermaster.com/pages/amd-ryzen-wraith-prism-rgb-software/
I don't know if my information was just missing for some reason like your cables, but there was nothing to explain all this in the packaging. I had to do a bit of search to know what they were for myself.