How to modify the open source Mongo Source Connector

I like to make the MongoSourceConnector start the change stream at an operation time. I like to add a new property. However, I am quite new in gradle and JAVA. Could someone let me know how to compile, debug, and test this project?
For IDE, I am using IntelliJ.

Check out the GitHub

There is a build section that tells you how to build the connector. Feel free to submit PR for your added properties!