This is a simple Kotlin based Spring Boot app demonstrating how to achieve an outbox pattern using Debezium Connector.
The whole solution is provided in the form of an end-to-end test.
Additionally, you can take advantage of docker-compose file, start the application locally and register connector using register-debezium-connector.sh. This will let you run the application on your local machine. Beforehand, you will need to download the debezium postgres connector plugin archive as it's described here: https://debezium.io/documentation/reference/install.html and Kafka Connect container relies on the content of this archive.