New setup of pgadmin4 with kerberos not working

All -

I am new to Postgres and Kerberos.
That said, I built out Postgres db. I got a keytab file from AD.
I'm sure it's all sorts of wonky but I did follow instructions and got
guidance.

Client based user authentication works from another linux server, after
running kinit.

What I can't get working is pgadmin4 as a client.

pgadmin4 local user account to the db works.
pgadmin4 AD account "abcuser" does not work.

pgadmin4 config_local... default except
AUTHENTICATION_SOURCES = ['kerberos', 'internal']
KRB_AUTO_CREATE_USER = True

Inside pgadmin4, I set up Connection tab like this:
Hostname = xyzserver
Port = 5432
Maintenance database = postgres
Username = abcuser
Kerberos authentication? = ON

*Error*:
connection to server at xyzserver (10.2.3.4) failed: GSSAPI continuation
error: No credentials were supplied, or the credentials were unavailable or
inaccessible. No kerberos credentials available (default cache: KCM:)

*postgresql.log :*
GSSAPI authentication failed for user "abcuser"
Connection matched pg_hba.conf line
"host all all 10.x.y.z/8 gss include_realm=0 krb_realm=AD.COM"

Docs talk about requiring kerberos keytab for pgadmin4 but I have 2
problems with that. 1) I don't have a registered DNS entry 2) I'm not part
of the AD team. It took work to get the keytab file for the db. I'd like to
avoid it for clients!