Have you installed the connector plugin in your Kafka Connect worker?
Once you’ve done that you need to create an instance of the connector. If you’re using Kafka Connect in distributed mode (which you generally should) then this is done using a REST call. There’s an example of what the JSON payload might look like in this post.
To get a general understanding of Kafka Connect and how to use it check out this Kafka Connect 101: https://developer.confluent.io/learn-kafka/kafka-connect/