default or selected kernelversion does not have config value CONFIG_LGUEST_GUEST.
Result is shown for kernelversion 6.5.1

Lguest guest support

modulename: lguest_device.ko


Linux Kernel Configuration
└─>Lguest guest support
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
Lguest is a tiny in-kernel hypervisor. Selecting this will
allow your kernel to boot under lguest. This option will increase
your kernel size by about 6k. If in doubt, say N.

If you say Y here, make sure you say Y (or M) to the virtio block
and net drivers which lguest needs.

source code: