Linux distributions may not have built-in support for newer Realtek chipsets.
Skip the driver that came with the CD (seriously, a CD in 2026?). Skip the apt install rtl8812au-dkms – that’s for a different chip. Here is the clean, reliable method.
: If Windows can't find it, you can download the drivers for the identified chipset:
The "rtl19oct" driver source was written for older kernels (3.x/4.x). Kernel 5.x introduced breaking changes in the net_device and wireless API.