default or selected kernelversion does not have config value CONFIG_R8723AU.
Result is shown for kernelversion 6.4.14
Realtek RTL8723AU Wireless LAN NIC driver
modulename: r8723au.ko
configname: CONFIG_R8723AU
Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Wireless LAN
└─>Realtek RTL8723AU Wireless LAN NIC driver
In linux kernel since version 3.15 (release Date: 2014-06-08)
This option adds the Realtek RTL8723AU USB device such as found in
the Lenovo Yogi 13 tablet. If built as a module, it will be called r8723au.
the Lenovo Yogi 13 tablet. If built as a module, it will be called r8723au.