default or selected kernelversion does not have config value CONFIG_RTW88_8821AU.
Result is shown for kernelversion 6.6.75

Realtek 8821AU/8811AU USB wireless network adapter

modulename: rtw88_8821au.ko

configname: CONFIG_RTW88_8821AU

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Realtek 802.11ac wireless chips support
└─>Realtek 8821AU/8811AU USB wireless network adapter
In linux kernel since version 6.13 (release Date: 2025-01-19)  
Select this option will enable support for 8821AU and 8811AU chipset

802.11ac USB wireless network adapter

source code:
drivers/net/wireless/realtek/rtw88/