default or selected kernelversion does not have config value CONFIG_8723AU_AP_MODE.
Result is shown for kernelversion 5.7.16

Realtek RTL8723AU AP mode

configname: CONFIG_8723AU_AP_MODE

Linux Kernel Configuration
└─> Device Drivers
└─> Staging drivers
└─> Realtek RTL8723AU AP mode

This option enables Access Point mode. Unless you know that your system
will never be used as an AP, or the target system has limited memory,
"Y" should be selected.