CONFIG_KEXEC_IMAGE_VERIFY_SIG is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64
default or selected kernelversion does not have config value CONFIG_KEXEC_IMAGE_VERIFY_SIG.
Result is shown for kernelversion 6.9.9
Enable Image signature verification support
configname: CONFIG_KEXEC_IMAGE_VERIFY_SIG
Linux Kernel Configuration
└─>Kernel Features
└─>Enable Image signature verification support
In linux kernel since version 5 (release Date: 2019-03-03)
Enable Image signature verification support.