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

PBlk Debug Support

configname: CONFIG_NVM_PBLK_DEBUG

Linux Kernel Configuration
└─>Device Drivers
└─>Open-Channel SSD target support
└─>PBlk Debug Support
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Enables debug support for pblk. This includes extra checks, more
vocal error messages, and extra tracking fields in the pblk sysfs
entries.