psql: fe_sendauth: no password supplied

Hi team,

I need your help to resolve an issue psql: fe_sendauth: no password supplied which we are getting by nagios plugin , we are trying to monitor the disk space and via  .pgpass for an authentication.

[root@viicinga-02 ~]# /mnt/common/local/linux/local/bin/check_postgres/check_postgres_disk_space.sh -H vikbcn-db2.vpc.prod.scl1.us.tribalfusion.net -f /var/spool/icinga/.pgpass_stby -w '60' -c '70'
Connection to vikbcn-db2.vpc.prod.scl1.us.tribalfusion.net 5432 port [tcp/postgres] succeeded!
psql: fe_sendauth: no password supplied

Regards,

Daulat