Stop Unravel.

<Unravel installation directory>/unravel/manager stop

Set the principal path and keytab and then enable Kerberos authentication:

<Unravel installation directory>/unravel/manager config kerberos set --keytab </path/to/keytab file> --principal <server@example.com>
<Unravel installation directory>/manager config kerberos enable

Apply changes.

<unravel_installation_directory>/manager config apply

Start Unravel.

<unravel_installation_directory>/unravel/manager start