If using a configuration file check the example:
https://www.mongodb.com/docs/bi-connector/current/reference/mongosqld/#mongodb-host-options
The auth: section is where that information is added.
If using command line options:
--mongo-username <username>, -u <username>
--mongo-password <password>, -p <password>
--mongo-authenticationSource <auth-db-name>
--mongo-authenticationMechanism <authMechanism>