Linux kernels (4.18+) include the standard snd-usb-audio driver. The CX31993 is fully compatible. Plug it in, and it will be recognized without any manual intervention.
Finding the official driver can be frustrating. Conexant no longer maintains a public consumer driver repository. Instead, the driver is usually provided by the manufacturer of your specific USB-C dongle (e.g., Avani, Abigail, Venture Electronics, or generic Chinese brands). conexant cx31993 driver