how do i specify the auth mechanism for Mongo?

Mongo DB supports multiple ways of authentication. By default, it uses a SCRAM-SHA-1 but this can be updated based on your database configuration.

For example, to use a SCRAM-SHA-256, simply add that to your Knowi Mongo Database Properties:

For more info on Mongo auth mechanisms, see below.
https://docs.mongodb.com/manual/reference/connection-string/#urioption.authMechanism