default or selected kernelversion does not have config value CONFIG_CFG80211_WEXT_EXPORT.
Result is shown for kernelversion 6.9.9

CONFIG_CFG80211_WEXT_EXPORT (not configurable)

configname: CONFIG_CFG80211_WEXT_EXPORT

Linux Kernel Configuration
└─>Networking support
└─>Wireless
└─>CFG80211_WEXT_EXPORT
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Drivers should select this option if they require cfg80211's
wext compatibility symbols to be exported.