Compass cannot connect to mongo replicaset in k8s

Hi,
I have create a mongo replicaSet in k8s, and I give each Mongo an external ip: port to allow external DB administrators to manage their data through Mongo compass, as follows:
mongo-0: 11.244.xxx.xxx:8000 (primary)
mongo-1: 11.244.xxx.xxx:8001 (secondary)
mongo-2: 11.244.xxx.xxx:8002 (secondary)
replicaset name: rs0

It’s ok to only connect to the primary one with pasting the connection string to compass like:
mongodb://user:password@11.244.xxx.xxx:8000/db?authSource=admin&readPreference=primary&directConnection=true&ssl=false

but when I want to connect to all of them with the below connection string:
mongodb://user:password@11.244.xxx.xxx:8000,11.244.xxx.xxx:8001,11.244.xxx.xxx:8002/db?replicaSet=rs0&authSource=admin&readPreference=primaryPreferred&ssl=false

I always get this error:
getaddrinfo ENOTFOUND mongo-0.mongo-headless.svc.cluster.local

Could someone help me with this?
Thanks.