mongo localhost/db_name -u user -p password --authenticationDatabase admin

mongo pod_service_name/db_name -u user -p password --authenticationDatabase admin

[thread1] Error: Authentication failed. :
connect@src/mongo/shell/mongo.js:263:13
@(connect):1:6
exception: connect failed

MongoDB server version: 3.6.12
Welcome to the MongoDB shell.
For interactive help, type "help".