Initialize client with keytab using Kerberos

Hello, I am trying to use https://github.com/mongodb-js/kerberos library in Node JS to do kerberos authentication. However when i do “principalDetails” and “initializeClient”, I am getting the below errors:
Server unknown while looking up error.
Cannot get sequence cursor from keytab.
I am in macos and i have my keytab file at /etc location.
Can you please let me know how can i get around this?