How do I tell if kerberos is active on my MacBook(2019 version)

The pipe symbol " | " is not a proper option. I'm assuming you wanted to use the the "list" option which requires the lowercase letter "L".

klist  -l

If you are not familiar with the command line, then be extremely careful using it since there is no safety net for the command line. If you use the wrong command or option, then you could end up destroying your data or even breaking macOS. Be even more careful using commands you find listed online since they may only apply to a very specific case. You should always review the commands and options before using them so you know what it does and the potential side effects. Even people with years of experience with the command line can make a simple typographical error that can have catastrophic results.

Kerberos sole purpose on a Mac is for Single Sign On (SSO) and it only comes into play when connecting to an Authenticating Directory System such Microsoft's Active Directory network. You can view Kerberos tickets using the Ticket Viewer application. This is buried in a folder in the System Folder. You can use Terminal to open it:

open: /System/Library/CoreServices/Applications/Ticket\ Viewer.app

If you don't see anything in Ticket Viewer then you're not connected to a Directory System and it's doubtful if Kerberos is active. With Activity Monitor you can use SSO as a search string and if you don't see anything there then Kerberos is not running.

If you use klist then type the following in Terminal:

klist --list-all

If all you see is:

Name CacheName Expires

Then Kerberos is not active.