Which connector?:

Confluent

Additional details:

Fivetran currently supports OAuth for the Confluent Cloud broker connection, but authentication for Schema Registry still requires Schema Registry API credentials. 

Confluent's Schema Registry can also work with OAuth. See: https://docs.confluent.io/platform/current/schema-registry/security/oauth-schema-registry.html

At my current company Confluent's Schema Registry ONLY works with OAuth :(

We request to implement OAuth for Confluent's Schema Registry, otherwise we are unable to use Fivetran for consuming events from Confluent.