kernelconfig_penguin
default or selected kernelversion does not have config value CONFIG_ATH9K_HTC_DEBUGFS.
Result is shown for kernelversion 5.9.9

Atheros ath9k_htc debugging

configname: CONFIG_ATH9K_HTC_DEBUGFS

Linux Kernel Configuration
└─> Device Drivers
└─> Network device support
└─> Wireless LAN
└─> Atheros ath9k_htc debugging

Say Y, if you need access to ath9k_htc's statistics.
As well as access to the FFT/spectral data.