How to debug LanguageTool in IDE (IntelliJ)

I want to debug LT on my local machine using IntelliJ

You need to check out the code from github and import it as a Maven project (File -> New -> Module from existing sources). Then you can start e.g. org.languagetool.commandline to debug the command-line version. Often it’s probably a better idea to debug a unit test.

Thanks