CONFIG_ARM64_PTR_AUTH is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Enable support for pointer authentication

modulename: pointer_auth.ko

configname: CONFIG_ARM64_PTR_AUTH

Linux Kernel Configuration
└─>Kernel Features
└─>ARMv8.3 architectural features
└─>Enable support for pointer authentication
In linux kernel since version 5 (release Date: 2019-03-03)  
Pointer authentication (part of the ARMv8.3 Extensions) provides
instructions for signing and authenticating pointers against secret
keys, which can be used to mitigate Return Oriented Programming (ROP)
and other attacks.

This option enables these instructions at EL0 (i.e. for userspace).

Choosing this option will cause the kernel to initialise secret keys
for each process at exec() time, with these keys being
context-switched along with the process.

The feature is detected at runtime. If the feature is not present in
hardware it will not be advertised to userspace nor will it be
enabled.

source code: