default or selected kernelversion does not have config value CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.
Result is shown for kernelversion 6.9.9
Enable bzImage signature verification support
configname: CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
Linux Kernel Configuration
└─>Processor type and features
└─>Enable bzImage signature verification support
In linux kernel since version 3.10 (release Date: 2013-06-30)
Enable bzImage signature verification support.