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

Physical Block Device Open-Channel SSD target

modulename: pblk.ko

configname: CONFIG_NVM_PBLK

Linux Kernel Configuration
└─>Device Drivers
└─>Open-Channel SSD target support
└─>Physical Block Device Open-Channel SSD target
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Allows an open-channel SSD to be exposed as a block device to the
host. The target assumes the device exposes raw flash and must be
explicitly managed by the host.

Please note the disk format is considered EXPERIMENTAL for now.

source code:
selects
CONFIG_CRC32

depends
CONFIG_NVM