default or selected kernelversion does not have config value CONFIG_RAMZSWAP.
Result is shown for kernelversion 5.4.229

Compressed in-memory swap device (ramzswap)

modulename:  ramzswap.ko

configname: CONFIG_RAMZSWAP

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Compressed in-memory swap device (ramzswap)
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Creates virtual block devices which can (only) be used as swap
disks. Pages swapped to these disks are compressed and stored in
memory itself.

See ramzswap.txt for more information.
Project home: http://compcache.googlecode.com/

source code: